"Suicide Drones"

Somewhere between a reusable unmanned combat aircraft and a cruise missile is the "suicide drone" or "drone missile" which is launched like a missile from a ground vehicle, warplane, or ship, but can loiter and swarm rather than simply flying directly towards its target as fast as it possibly can. One or two of them could even be carried in the truck of a civilian sedan, removed when needed, and deployed by one or two operators who drove the sedan to the launch point.

The "Dahir İnşaat anti-tank drone-missile concept" illustrated in the embedded video clip below fills this conceptual space.

There isn't yet a production model is use. But none of the technologies involved are revolutionary. 

The targeting of individual missiles is something already widely done with similar sized anti-tank guided missiles and "smart bombs" since the 1980s. Satellite images, widely available surveillance drones, and forward observes with glorified cell phones that were used by special operators and CIA agents a decade ago, shortly after 9-11, can identify targets. The artificial intelligence software needed to manage swarms of drones without individual human operators has been demonstrated repeatedly, for example, in the opening ceremony of the 2021 Summer Olympics in Japan this month. Small quad copter drones are already used routinely in military and civilian applications. Guided missiles and bombs routinely have an initial rocket delivery system with navigating equipment that pops out when needed after an initial launch to keep a guided missile or bomb on course. The warheads themselves are 1960s technology. This concept simply puts a lot of pre-existing technologies in a single package in a straightforward way.

Honestly, it is rather terrifying.

This technology continues the trend of making heavy armored vehicles or moderately reinforced bunkers almost obsolete against opponents that can afford this kind of anti-tank weapon. 

It also provides yet another of many highly effective approaches to defeat surface warships by simply exploding large number of anti-tank warheads all over their decks (in addition to manned or unmanned missile boat swarms, coastal diesel-electric submarines with torpedos, anti-ship missiles including hypersonic anti-ship missiles deployed from launchers on land or ships or submarines, sea mines, manned or unmanned warplane or armed helicopter delivered bombs, missiles and torpedos,  missiles or torpedos delivered on ships disguised as civilian freighters or fishing boats, and infecting ship crews with debilitating contagious diseases).

Its modest size makes it possible to deploy suicide drones in large swarms from all sorts of platforms as modest as general aviation aircraft, pickup trucks, or fishing boats designed for civilian use. 

Air dominance is a powerful asset in war that the U.S. and its allies almost always holds these days, but while that renders tanks, armored personnel carriers, artillery batteries, ships, large warplanes, and modestly reinforced bunkers almost impotent, it only works if a target can be located and destroyed before it disappears.

In swarms, suicide drones can overcome even quite effective active defense weapons that shoot down incoming missiles with directed energy or projectiles, by simply overwhelming the ability of the active defenses to destroy all of the incoming suicide drones at once.

While they are presumably not cheap, the lion's share of the cost goes to the R&D design budget and/or patent royalties for the designer. Once you have the design, the cost of manufacturing one of these missiles itself wouldn't be overwhelming and only the guidance system requires anything approaching really high tech manufacturing process.

For the cost of one $80 million fifth generation jet fighter you could buy 4,000 suicide drones and their associated launchers, if one could get the cost down to $20,000 each. This kind of unit price would be quite manageable if the details of a design stolen and the relevant software were stolen once by a spy and then posted on the dark web. But a swarm of just 40 suicide drones is more than enough to carry out a devastating attack, unmatched in recent memory, on far more sophisticated U.S. or "near peer" class military targets.

This offensive capability, the lack of a need for big and expensive launchers, and these economics could make this kind of weapon are real equalizer vis-a-vis a major military power like the United States. 

One can imagine this kind of system in the hands of a "mid-tier" sovereign nation opponent (like Ukraine, Poland, Syria, Turkey, Iran, Myanmar, Vietnam, Nigeria, or Chile), or an insurgent force fighting a proxy war with backing from a more affluent country (like China or Russia or the U.S.), or insurgent groups with backing from affluent individuals who are part of a non-governmental political movement (like the affluent Saudi Islamists cadet line royals outside and in opposition to the Saudi Arabian government, who have bankrolled the Taliban in Afghanistan).

It should be more of a concern, even, than the proliferation of nuclear weapons. Suicide drones very effectively serve well established military objectives. 

Strategic nuclear weapons have vastly more destructive capacity that swarms of anti-tank suicide drones, but destroying whole cities of civilians while causing severe environmental damage and potentially triggering national or global extinction level retaliatory nuclear strikes is almost never a military objective.

Also, nuclear material for nuclear warheads is tightly controlled and hard to come by, so when a country like North Korea or Israel or Pakistan or Iran manages to get nuclear weapons, it can't make very many of them.

In contrast, any country with enough of a manufacturing base to make artillery shells or unguided rockets or radio-controlled quad copters, and enough money and wit to buy commercial off the shelf drone guidance systems and other sophisticated parts in the civilian market without attracting too much attention, can build suicide drones. Dahir İnşaat, which came up with this concept, is a small Turkish engineering company.