Blog layout

Bear with me - I'm trying to renovate this place.

I will create a proper title banner later.
Maybe this year. Maybe not.



Infantry agility past and present

Have a look at this, 1:47 min onward:

I didn't look specifically for a video about Germans, but simply one of the many WW2 videos where running infantrymen are shown (I typed in 'infantry attack' in YT and found this as 3rd video), in fact I had hoping for a Bersaglieri film.

The thing that strikes me is how quickly these actors can move (and the effect of a possible acceleration by manipulating camera film speed cannot be great, for such acceleration is usually visible). Their equipment is in the 10-15 kg range in my opinion, and only the machinegunner is at the upper end of that range.

I've seen people moving quickly a lot, of course. It's just that modern Western infantrymen are rarely seen running in action - they're usually much slower than that or run but a short 20-30 m sprint once in a while. I understand that - I'm 20-25 kg heavier now than during my (mostly skinny) Bundeswehr days and I notice my walking changes when I carry 10 kg. It feels different in the feet especially. The feet are signalling me that they would tire out quickly under that load. I myself was never nimble or much inclined to move quickly with a 10-20 kg load.

Let's come back to the Bersaglieri. They are the traditional light infantry of the Italians, and to some degree an elite compared to the regular infantry. They also had (and still to some extent have) an emphasis on speed.

Back in ancient times there was light infantry running next to cavalry if an army leader judged his cavalry wings to be inferior. This cavalry-supporting infantry would join the melee between cavalry and cavalry and often times decide it with their numbers and spears and/or javelins.
There hasn't been many examples of such running infantry for a long time, when the early 19th century Zulus and their still hard to believe endurance at running entered the stage and were documented by the Boers and British.

The Bersaglieri show off their emphasis on running and fitness in the most ludicrous way; they run on parades.

It's hard to take them seriously after watching this, but the attitude may be worth consideration!*

- - - - -

Now a part for Germans:

Ich habe die Sache mit dem Gauland und Stolz in den Nachrichten gesehen. Zitat
„Man muss uns diese 12 Jahre nicht mehr vorhalten. Sie betreffen unsere Identität heute nicht mehr. Und das sprechen wir auch aus.“ & „Wenn die Franzosen zu Recht stolz auf ihren Kaiser sind und die Briten auf Nelson und Churchill, haben wir das Recht, stolz zu sein auf die Leistungen deutscher Soldaten in zwei Weltkriegen.“
Ich fände es dümmlich wenn es nicht eine offensichtlich absichtliche Provokation wäre. Zudem ist es, was Amerikaner eine "dog whistle" nennen; etwas im Wortlaut Unverfängliches sagen, bei dem man davon ausgehen kann, dass es eine bestimmte Klientel in einer bestimmten anderen Bedeutung interpretiert. Es ist eine Art minimale plausible Dementierbarkeit, die dann aber doch fast jeder durchschaut.
Die zwei Sätze des Zitates stehen ohnehin in Dissonanz zueinander; entweder da ist eine starke Verbindung oder eben nicht. Wennd a keine starke Verbindung ist, dann wäre Stolz ein Schmücken mit fremden Federn.
Aber "das Recht" stolz zu sein hat jeder, ob's Sinn macht ist eine ganz andere Frage.

Ich finde es dümmlich, stolz sein zu wollen auf das, was andere mal getan haben oder nicht. Man kann sich an dem was andere getan haben erfreuen, man kann sie bewundern, aber stolz sein sollte man nur auf eigene Leistungen oder auf den eigenen Nachwuchs (was dann doch wieder ein Stolz auf die eigene Erziehungsleistung ist).
Dementsprechend verwende ich historische Videos zum deutschen Militär usw. wohl fast nur deshalb über das statistisch Wahrscheinliche hinaus, weil es eben sprachlich naheliegt oder in der Sache begründet liegt.


*: I myself hate running, but it's not essential to anything I do these days.


Daesh is finished

Just to state the obvious; my expectation that the strategic idiots of daesh will defeated themselves by turning just about everyone into an enemy has come true. They're in control of a road and a mere two towns in Syria as of today.


It didn't work out for Napoleon, it didn't work out for Hitler. Only the Asian steppe people from Huns to Mongols were able to afford having that many enemies because their strategic mobility was far superior, and they could (usually) deal with them one after the other.* "AQ" had such strategic mobility, but being a mere movement fashion they had their up and down, and have become irrelevant.

I never understood why everyone got so agitated about daesh. They were guaranteed to lose and frankly, they were and are the problem of the Syrians and Iraqis. The supposedly daesh-aligned criminals in Europe merely picked the asswipe fashion du jour, and would have most likely have picked some asswipe fashion regardless of daesh's existence anyway. There was never a real link between bombing daesh and criminals in Europe, nor between bombing daesh and daesh ultimately losing. The bombing may have hastened daesh's downfall while also helping daesh to recruit more idiots, though.



*: The Huns were finally stopped when they had so many footmen allies, captured cattle and booty with them that the West Romans and Visigoths were able to fight them unitedly.


The math of war or peace

A proper equation for determining whether to go to war or not would look approximately like this:
 (An egoistical decisionmaker would go to war if the equation is true.)

I didn't get the formula right 100%, but I suppose it's close enough to convey the idea.  This calculation is impossible to make, for one cannot even imagine all possible scenarios, much less determine their probability and weigh them accordingly. The human brain simply doesn't work like that, it's more fuzzy. We're led by feelings and guesses. Some philosopher once called it the ultimate insult to humans that it's actually our subconsciousness that's in total control of our actions. Our consciousness is more like a commenter. We can consciously understand that decisionmaking would be optimal if we calculated some formula such as the one above, but then our subconsciousness simply does something, whatever that may be.

This is a curious thing, for I suspect that the equation that's really in use is an entirely different one, a two-variable equation. Something close to this:

with Z being between 0 and 1 and representing the decisionmaker's attitude towards risk (risk aversion, risk neutrality or risk taking behaviour).

Maybe some research into this by psychologists and game theorists could provide clarity (honestly, I did not do a dedicated literature research on this beforehand, but I found nothing like this in literature yet).

This could explain a lot (especially the observable marginal importance of costs of warfare on many decisionmakers), and it could clarify a lot for deterrence policies. There would be but two variables that matter; probability of military defeat and the decisionmaker's risk aversion. The problem with aggressors is that the potential defender would most rarely be able to pick the potential aggressor's decisionmaker, of course. Maybe that's why almost everyone seems to emphasise the probability of military success or defeat so very much.



The changing battlefield air defence (II)

Part I of this series showed how technological progress led to radical changes and how important the effective ceiling difference between light and heavy AAA or (V)ShoRAD and area air defences were.

This time I'll argue that it's become more complicated. The rise of missiles with much more autonomous seekers especially since the 90's (examples AIM-120, MICA, Aster, R-77 - the earlier AIM-54 did not trigger much) brought lock-on after launch (LOAL) into the air war repertoire.

This is hugely important in many ways, but one is of special interest: Nowadays the missile launcher unit does not need a line of sight  to the target or even only the point of intercept any more. It suffices if it gets targeting data that was generated based on distant sensors (networked warfare). The USN demonstrated this (quite late - it should have been possible two decades earlier) with a SM-6 missile that was launched based on aircraft (E-2D or F-35) targeting data only, not using any of the launching ship's sensors.

This unhinges the old two-layered air defence just as much as the advance in airborne ground targeting sensors (imaging infrared, imaging radar) in the 1980's: (V)ShoRAD simply doesn't protect much any more. Well-equipped hostile air power could engage ground targets effectively with impunity. Meanwhile, area air defences with LOAL capability combined with airborne (or land-based forward and thus line-of sight) targeting sensors could defend not only against those ShoRAD-immune threats, but also engage non-line of sight targets (such as aircraft and especially helicopters at very low altitude) that were previously the prey of (V)ShoRAD only.

This leads to two divergent paths for battlefield air defences:

(1) Missile launcher forward, airborne targeting sensor

An AEW aircraft of fighter provides the targeting info, and a mere missile launch container or rack on a vehicle platform with manoeuvre land forces (such as a mechanised battalion battlegroup) provides the LOAL missile with enough chemical energy for area air defence and a high effective ceiling.
The weakness of this approach is in the questionable air support; AEW aircraft could be destroyed or pushed too far back, and fighters would hardly be on station and facing the right direction (few have more than 180° radar field of view) much of the time. Land forces with inadequate air power support - that is, exactly the ones in need of battlefield air defences against manned combat aviation - would find such means of targeting to be unreliable.
The hostile air power on the other hand would still face great risks engaging such land forces, as the network of airborne radar and forward missile launcher would be intact at times and unpredictably so.

(2) Sensor forward, missile launcher more or less "behind"

This is a relevant scenario when you look at a smaller scale. The previous path was interesting with a network of hundreds of kilometres expanse. This second path is rather about the difference between forces rather close to the launcher. A battalion battlegroup or even entire brigade from a country with a poor military budget (such as Romanian land forces, for example) could fight alongside a much better-funded brigade. The low budget force could then use highly survivable sensors (say, Rheinmetall FIRST, RAFAEL Helispot or SAAB Giraffe 1X with on-the-move activity) to provide targeting data and the neighbouring force could use its stocks of expensive LOAL area air defence missiles to protect its brothers-in-arms. Armoured recce and irregulars that operate around a well-budgeted brigade could also benefit from such an air defence umbrella if only they have what it takes to provide good-enough and trusted targeting data.

the old-school (once rather gold-plated) Gepard SPAAG
Germany got rid of its Gepard SPAAG and its Roland battlefield point defence missile systems years ago, and the renewed attention on the actual constitutional mission of defence has led to a renewed interest in battlefield air defence. There are even some bureaucratic requirements; as least some forces need at least a fig leaf of battlefield air defences, and the leftovers of 1980's Stinger stocks are not taken seriously any more (that is, if they exist in Germany at all any more).

There are enough nostalgic people who think of reintroducing Gepard or introducing something similar to Tunguska. There's (justifiably) very little love for the puny LeFlaSys Ozelot which depends on mere ManPADS even though it has a better effective range and ceiling than a 35 mm gun.

I think these thoughts of reviving the 1970's and 1980's concept of battlefield air defences are nonsense. To do such a thing would be wasteful, and if we did it we should at the very least use a less easily-countered guidance principle; laser beam riding (RBS 70 NG with Bolide missile). But such (V)ShoRAD systems have tiny niches nowadays; mostly short exposure targets of opportunity (mostly battlefield helicopters) and keeping low quality air threats at a safe distance. They could also be used by armoured recce to besiege hostile forward air bases (harassing hostile aircraft on their landing approach). These niches are why I mentioned them as a ShoRAD solution for budget brigades.

Radar-equipped LOAL missiles tend to be expensive, and seem to keep becoming more expensive. I wouldn't be surprised if the AMRAAM-ER costs USD 1.5 million per copy even if Germany ordered 1,500 such missiles. (That would be still acceptable if it achieves a mere 10% kill probability against combat aircraft in wartime conditions!) Infrared sensor LOAL missiles such as IRIS-T SL offer much less range (thus also much less ceiling) and are much more questionable for look-down engagements (against very low altitude targets, for example), so their somewhat lower price makes them attractive as complements (also in order to achieve redundancy of guidance principles), but they cannot protect nearly as much as a well-functioning and (hopefully) not-yet countered AMRAAM-ER could protect.
Anyway; all LOAL missiles are awfully expensive and in my opinion too expensive for poorly funded land forces. Countries such as Bulgaria, Croatia, Hungary, Romania, Greece, Portugal, Belgium, Czech Republic and Slovakia should prioritise other equipment and should be able to expect some support from their allies in this regard.

I think the way to go for a rather well-funded European army such as the Heer is to have a multi-role brigade radar, but to not depend on it for battlefield air defence. Other (infrared, infrasound) sensors should complement it and the brigade should have rocket launchers with area air defence LOAL missiles (AMRAAM-ER would fit the bill) to project a sizeable battlefield air defence umbrella that can even protect less well-funded brothers in arms nearby. This was all about manned air threats and comparably expensive air targets, of course. There's more to air defences.



edit: For clarification I'd like to add that I do not mean missiles such as Patriot, ESSM Blk I or SM-2 as "LOAL" missiles. Such missiles lock on their target sometimes long after launch, but they have no ability to lock on targets that are not in line of sight to an illuminator radar - that's a huge problem with their SARH guidance.


The changing battlefield air defence (I)

I noticed that I didn't explain my interpretation of all things battlefield air defence properly, so I'll do this military theory series to explain. Keep in mind - as always - it's but an interpretation, and I may be wrong. One good reason to believe me to be wrong is that air defence is a very technology-driven area of warfare, and thus outsiders are prone to forming wrong conclusions because of incomplete information. What I'm writing here may very well be true, but it may just as well be outdated by 10-20 years concerning the state of the art. Also note that I will ignore ballistic missile defence, naval air defence as well as 'strategic' land-based air defence in this series.

First, the military history part:

Historically, battlefield air defences began with 75-88 mm guns mounted on platform motor vehicles. They were meant to provide a mobile force to destroy enemy airships and tethered balloons. Ambitious plans called for hundreds of such self-propelled anti-air guns even before the First World War. The First World War showed that the external ballistics of such guns were insufficient to repel tethered balloon deployments to a distance from which their observation was useless. Airships could not dare to fly over territory defended like that in daytime, though. Such anti-air guns shot a lot at aircraft, but the fire control was insufficient even against the less than 200 kph fast, less than 5,000 m high-flying targets. Barrage fires were used to protect the own tethered observation balloons against hostile aircraft. Machineguns proved to be important to discourage or weaken the attacks by aircraft on ground forces.

Little happened during the Interwar years, but some of the WW2 AAA were developed, among some anti-aircraft gun solutions that were failures. Much was invested in fire control, but without the appropriate attention to the correct approaches to fusing and shell steel brittleness.

During WW2 all guns weaker than 30 mm proved to be a disappointment; 20-25 mm guns were effective only at very short ranges, and with a great volume of fire. They required multiple hits for one kill, so they were more a deterring and damaging anti-air arm than a killing one. 30-40 mm guns were powerful enough to kill most aircraft with a single hit, but their range was insufficient against medium bombers. Most 37-40 mm guns had a poor rate of fire and were effective to about 3,000 m diagonal range. Their shells were often set to self-destruct after about 3,500-4,000 m of flight. The expense of such a battlefield air defence (including the usually necessary motor vehicle as tractor and the often preferred additional motor vehicles to enable a battery to march as one) was great, and even thousands of such guns were inadequate to properly defend against the fighter-bomber and Shturmovik threat.

Heavy AAA was of little importance to battlefield air defences. Intermediate AAA (45-55 mm) was a gap-filler that was hardly ever used.

Post-WW2 radio fire control became much more widespread, though even the self-propelled anti-air guns with their expensive platform vehicle and support often lacked radar fire control (examples M42, ZSU-27-2). technologically sound SPAAGs were available around the year 1970 (ZSU-23-4, Gepard, AMX-13DCA), but a vehicle such as a Gepard did cost three times as much as a concurrent main battle tank (Leopard I), so the SPAAG force that was mostly meant to protect the tank force almost approximated the latter's costs. Less ambitious SPAAGs were in service as well, with incomplete radar fire control (example M163 VADS) and accordingly cheaper, but also much less capable and thus required in even greater quantity.
Missiles began to complement guns for battlefield air defence in the late 60's, famously the semi-mobile SA-6 batteries of Yom Kippur War fame. Man-portable missiles (Redeye, Igla) and air combat missiles adapted for air defence (Chapparal) were of little consequence in the 70's because they were limited to tailchasing with their infrared seekers. Dedicated self-propelled air defence vehicles (Roland, SA-8) were more capable, but also expensive (and their towed equivalents such as Rapier were a rare compromise).
A reasonable, but not very mobile  budget solution of the 60's to the 80's was to combine a fire control radar with several towed guns (usually 30-57 mm calibre). Heavy AAA had largely lost its relevance because the long time of flight beyond 57 mm range and the high speed of turbine-powered aircraft made preventive evasive manoeuvres extremely effective against guns.
An exotic system was the Swedish RBS 70 with its laser beamrider guidance, which allowed a crew-portable battlefield air defence to engage air targets from all aspects within a reasonable range.

The 80's saw little change; the arrival of infrared guided missiles that would almost reliably lock on aircraft head-on made them a bit more effective (though their effectiveness was exaggerated).

Post-Cold War we saw a rise of a few SPAAG designs with complementary missile armament (Tunguska, LAV-AD), but they shared an important problem with most other battlefield air defences; the effective ceiling was lower than the maximum effective altitude for precision attack on land forces. The sensors (particularly thermal cameras coupled with instant laser rangefinders) had advanced to a point by the late 1980's that most battlefield air defences were merely able to push air threat above the effective range of anything but short dive bombing/rocketing attacks (= what the Soviets continued with good success and very few losses in Afghanistan after the arrival of Stinger missiles).

Area air defence batteries with longer-ranged, higher-ceiling missiles would be needed to complement the short range air defences (ShoRAD), but particularly the NATO countries trusted their air forces to achieve air superiority if not air supremacy quickly, and didn't invest much in such systems. What systems were available (mostly Patriot, IHAWK, Skyguard Aspide, recently SAMP/T) were at most enough to satisfy air defence requirements for support assets behind the manoeuvre forces, including bridges, airbases and headquarters. The approach of using (V)ShoRAD to push hostile air threats up where they could be engaged by area air defences was what caused much trouble to the Israelis in 1973 when they faced the SA-6, but it was established already in the Yom Kippur and Vietnam War that attacks on the area air defence batteries (and in particular their radars) would unhinge this teamwork. Russia, France, Israel and the UK committed some resources on dedicated equipment to locate and defeat such radars, but it was the U.S. that invested greatly and used this investment to bomb the Iraqis almost with immunity, but it was the Yugoslavs who showed that tactics could degrade such anti-radar efforts from destruction (DEAD) to suppression (SEAD), which meant that a sizeable share of the superior hostile air power was fixed in the anti-air defence mission indefinitely. The rapid consumption of expensive anti-radar missiles would be unsustainable and unsuitable for a large air war.
I recommend "On Air Defense" as a book to those who want to read more on the history of air defense.



"U.S. Army unprepared to deal with Russia in Europe"

But the assessment details a series of “capability gaps” the unit has identified during recent training with Ukrainian troops with experience battling Russian-backed separatists, who have used cheap drones and electronic warfare tools to pinpoint targets for artillery barrages and devastated government armored vehicles with state-of-the-art Russian antitank missiles.
Some of the shortfalls, like the brigade’s lack of air defense and electronic warfare units and over-reliance on satellite communications and GPS navigation systems, are the direct results of the Army's years of fighting in Iraq and Afghanistan, where the enemy has no air power or other high-end equipment and technology.
“The lessons we learned from our Ukrainian partners were substantial. It was a real eye-opener on the absolute need to look at ourselves critically,” Col. Gregory Anderson, who commissioned the report earlier this year during his stint as the brigade’s commander, told POLITICO after it had obtained a copy of the report. “We felt compelled to write about our experiences and pass on what we saw and learned.”  

This is ridiculous. Nobody needs to talk to Ukrainian combat vets to learn these things. Practically all senior NCOs and senior officers worth their pay knew this, and for a long time.

The article didn't even mention the poor 155 mm artillery of the brigade or that its anti-tank defences are almost wholly dependent on the Javelin missile which can be defeated with mere multispectral smoke (a defence that doesn't even require any updates to tanks, just some cheap smoke munitions).

The problems likely go much deeper than that: There's a reason why U.S.Army personnel sucks at almost all multinational competitions, be it tanks, artillery infantry or whatever; it can be explained with the extremely common complaint about poor training of basic soldiering skills. You can hear and read these complaints almost everywhere.
The root cause appears to be the personnel system that prohibits any continuity. Personnel is getting moved into and out of units that quickly that any year-long training plan to build up qualification from basics to small unit level to unit level to formation level is moot. Too much personnel gets transferred out after learning the early stages, and replaced by new personnel that missed the basics training. There are also more mandatory training days per year than there are days available per year. The captains cannot possibly devise a training plan that follows all orders about mandatory training, an obvious failure of TRADOC.

To fix their personnel system (which has been demanded by reform proposers such as Vandergriff for decades) does not require additional money. It may even save a lot of money. I'm not sure how much of Congress' micromanagement-by-laws gets in the way of personnel reform, but I'm quite sure it should be done. In two decades I've seen great many calls for such a reform, and no-one standing up in defence of the current personnel system. The symptoms are really bad and warrant change.




Back when I joined ...


I recently found an old diary of mine. It encompasses more than a year, pages full of codes for repetitive stuff that I did all the time. And kind of miss doing.

The last day in the diary isn't on the last page, by far. It reads
8:50 - 12:00 DB, Ankunft in der Kaserne,
It was the day I left for military service (DB = Deutsch Bahn, railway / Ankunft in der Kaserne = arrival at the barracks). My young days had ended abruptly.

I'm sure I forgot most of the first weeks and months in the Luftwaffe, but I didn't forget the first day. I arrived among the first six recruits that day, and the consequence was we were told to go into a room where three bunk beds were standing. Then we had to wait, for hours. The basic training was - like just about every other education or training I ever had - a thorough disappointment. We learned almost nothing, but this was already more than some could digest. 

One draftee was 2.06 metres tall and angry he hadn't told his draft official that he's 2.10 m, for then he wouldn't have been drafted away from girlfriend, own apartment and full time job. The recruitment office had no means to measure past 2 metres length, he could have fooled them.
He got a sweat suit and running shoes within days, and nothing else for the first three weeks or so. His supersized clothes and boots were simply not available in the barracks themselves. He also got a "Null Kilogramm Schein" (zero kilogram certificate) from the medical doctor - this excepted him from carrying anything but his clothes due to his joints and back issues. He still was kind enough to carry helmet and rifle on occasion - even though nobody could order him to do so. (Others got 10 kg Scheine.) Nobody could figure out what the Bundeswehr wanted from him. Eventually, he ended up as sauna boy; handing out towels and taking them back. Supposedly this was an all-essential job, for without such a sauna boy who kept watch the sauna supposedly would become filthy. Go figure, it was used almost exclusively by officers and senior NCOs.

There were plenty such anecdotes, and they fed my disgust for bureaucracies more than any theoretical education in economics ever did.

The most useful skill that I learned in those first months in uniform was how to fall asleep in an instant. We were kept busy artificially all the time, and the permanent stress made us take naps at every opportunity. When the order came to "self-study" in our dormitory, we all calmly went to the six-stool table there, sat down, crossed arms on the table, dropped our head and fell asleep in no time.

Still, with all that stress the Bundeswehr did not in any course or at any time train me the way all other trainings and educations went; usually it's too little learning for my taste, too much exercising for my taste. The Bundeswehr only met the "too little learning" part. I'm not joking; I did 30 push-ups in a minute every day during the months before I joined the Bundeswehr, at the end of basic training I was barely able to do 20 push-ups and when I left the service I was down to 15.

The Bundeswehr got considerably worse in the years since I left it, so I was told. Repeatedly.



Weird marketing pushes for American right wing blogs

There's a marketing technique in which  a service loads certain blogs a couple times to let certain URLs appear in the traffic source of said blog. The blogger is then enticed to look why suddenly dozens if not hundreds of visitors came from that place.

The technique is no issue for bloggers with a huge audience, but it skewers the stats and annoys bloggers who have but hundreds of real visitors a day, like me.

Now I can see these things in my stats of the week's referring URLs.

What I can observe is a weird shift; usually the URLs that got pushed like that were assorted, often scammers or companies that offer services to bloggers.

This changed rapidly, and suddenly; now mostly American right wing blogs get promoted this way,  and with substantial "visitor" counts (around 40-120 a week). It's not all political blogs, though; there are also two couple (non-commercial) law-related blogs and one medical-related blog involved. Not a single political non-right wing blog was promoted, though.

The shift was so sudden that a decentralised motivation is utterly improbable. I suspect somebody with enough money decided to promote a certain portfolio of American right wing blogs in a fairly invisible way (invisible compared to fake followers on twitter etc.). An alternative explanation would be that somebody promoted this way of promotion, but it's quite implausible that bloggers with very few posts per month would pay for such a promotion. Their inclusion makes rather sense as providers of plausible denial or as part of a third possible (unlikely) explanation; a bug inside the statistics software of blogger.com.

And yes, I checked. These right wing blogs did not suddenly begin to link to me. These are no real referrals. I know a couple right wing bloggers who did link to me occasionally, and they are not among the ones who now benefited from that promotion.



Very low level air defence against flying drones

I've pointed at the issue of aerial drones as a battlefield air defence challenge that cannot be met with traditional dedicated battlefield air defence hardware. You simply cannot defend against 5,000...50,000 € drones by firing expensive missiles at them, and the handful of self-propelled anti-air gun crews cannot really defend other troops against drones that approach at less than 10 m altitude.

Small arms have to be the (metaphorical) last line of defence, particularly against the smallest drones - but small arms have a very poor probability of hit against drones a few hundred metres away if the user can spot and identify a drone at such a distance at all. This isn't trivial at night, for example.

Radio jammers have been developed, deployed and used to disrupt the radio command link and/or satellite navigation of flying drones.* A properly designed reconnaissance drone that encounters this would use its inertial navigation capability** to return to a pre-designated landing point, usually this would be the take-off location. The drone user would likely regain control before the drone would arrive. Well-designed autonomous killer drones would be most unimpressed by radio jamming.

Air defences that depend on acoustic sensors for alerting would be incapable of detecting gliding drones or drones that fly like an owl; silently.

Daylight and UV cameras would not suffice at night time.

Radars would have difficulty telling birds from drones that emulate bird behaviour, and the emissions might be treacherous.

Laser radar (LIDAR/LADAR - essentially scanning the sky with a laser) is incapable of identification as well - and I doubt it would be practical for 3D search for tiny objects.

Net projectors tend to be very limited in range and are bulky.

Hard kill weapons may reasonably range from 5.56 mm to 30 mm, and at 30 mm an electronic-timed  cannister round as in the German Puma IFV may be used. The timing would require some information about range, though.

- - - - -

Well, here's a possible standard subsystem for use on military vehicles. It's not totally specialised, so the introduction of such hardware may be realistic:

Think of a remotely-controlled weapon station (RCWS). The installed weapon would ideally be some .338 revolver machinegun with a controllable rate of fire, but realistically it would be an ordinary 7.62x51 mm machinegun (then preferably MG3). The traverse would be 360°, elevation -15°/+90°.
a typical RCWS, this example has a 12.7 mm gun
The RCWS would have two rings of microphones which can be used for sniper detection, can feed info in the radio network for triangulation of artillery and mortar fires, detection of helicopters and the microphones could also detect the typical noises of drones. They wouldn't be 100% reliable, but most drones might be noticed at useful distances.
There would also be a ring of four wide field of view uncooled infrared sensors, and one coaxial uncooled infrared sensor with zoom. The ring would provide a permanent all-round stare to detect threats and to provide the vehicle crew with all-round day/night vision. They could detect muzzle flashes and patterns/movement of ground targets as well. These staring sensors should detect drones at all relevant distances; drones should not be able to identify a stationary vehicle before its RCWS sensors detect them. The sensor range may thus be greater than the weapon range (a correct warning is very useful in itself).
The coaxial sensor would be used for identification. Its effective range should allow identification of targets (all kinds) at the effective range of the gun against those targets. A coaxial laser rangefinder could provide range information on the target and greatly improve the weapon's accuracy. It could also be used as an interrogator device of an identification friend or foe system in which the lased target may respond with coded radio message if it's friendly. Such a laser could - if the wavelength fits - be used for simulation purposes in training systems like MILES and AGDUS.

An alternative setup would use a rotating scanning uncooled IR sensor that switches to coaxial mode once a target is found. This approach was used by dedicated air search sensors like AD/AD, FIRST and also a couple less well-known systems (including a Swedish and a French one, but I keep forgetting their designations).

The all-round staring sensor setup could also be used for an active protection system; or an active protection system's staring sensors could provide the air search for a RCWS that has only a coaxial sensor. 

Either way, having enough infrared air search is going to be expensive; ten thousands of Euros per vehicle including necessary spare parts. The whole package could easily cost 200,000 € even with competent project management and a large production run. It would cost more if active protection system launchers are included as well and this does not include a software-defined radio to fully exploit the potential by networking the stations and integrating them into the formation's air defence and arty/mortar detection.

Now think of thousands of such RCWS deployed with an army corps, installed on combat and non-combat vehicles. Low altitude drones would have a much harder time. Autonomous killer drones could still overwhelm defences if they attack as a saturating swarm, of course. The only realistic defence against a swarm of autonomous killer drones may be another swarm of autonomous killers drones.

Autonomous killer drones are  quite a challenge, but currently there's little indication that the armed bureaucracies could cope with the much less difficult well-designed recce drones. There are hardly any programs for developing or buying equipment with the recce drone challenge in mind (known to me). The directional radio jammers won't help against well-designed drones and they are apparently never integrated with proper sensors.


*: Many companies came up with simple directional (mostly Yagi-type) antennas installed on something rifle-like to jam the radio bands relevant to commercial drones and pretend that they are oh-so great. Such technology is worthy of a 1930's electrical engineering student's homework.
**: Accelerometers are cheap nowadays, that's why there's a  the quadcopter boom; quadcopters require accelerometers for stabilisation.