This idea for a combat vehicle has been overtaken somewhat by changes in world events and the dissolution of the USSR. Such vehicles designed to attack an advancing enemy's lines of communication may still be useful for nations who have unfriendly neighbours and may work well with the militia defence that I have described. Alternately such vehicles could be inserted by helicopters deep in the enemy's rear, as was done with the ASU-57 in Ogaden.
The Russian ASU-57 air assault gun resembled a Bren gun carrier with a glacis mounted medium cannon, and was the size of a small car. This weapon is not effective against modern tanks, but will still easily destroy most lighter armoured vehicles. There is potential for a dedicated antitank platform that resembles a ASU-57 mounting launch boxes/tubes for ATGWs. This would give the vehicle anti-MBT capability and also a cost effective way to destroy trucks and light armour. Being only three feet high, such a vehicle would be smaller and more easily camouflaged than an APC or HMMWV. It would be highly mobile and capable of being easily airlifted, even by relatively small helicopters, giving it great strategic mobility. The 57 x 480Rmm gun should be capable of destroying most modern armoured vehicles other than tanks.
The 40mm/L70 Bofors cannon used on the Swedish CV90. Use of this weapon would be desirable if the anti-tank vehicle is operating with a force who's IFVs or ADA vehicles use this weapon.
The British RARDEN 30 x 170mm High velocity gun. This is a semi-automatic and burst fire weapon, which encourages efficient use of fire. The Oerlikon KCB uses similar ammunition but is fully automatic and belt fed.
The Oerlikon KCA and Mauser MK 30 are single barrelled weapons using the same 30 x 173mm round as the GAU-8 cannon used by the A-10 aircraft. The Boeing (now Alliant) Bushmaster II 30mm gun can fire either 30 x 170mm or 30 x 173mm rounds.
The Mauser RMK-30 30mm Automatic recoilless cannon.