Anti-Tank Missiles are only available for the NATO A-10 and the PACT Su-25. 4 are provided per take off and resupply.
These require a lock-on to fire and will only lock-on to creeps, AAA, and FOBs. They will lock onto MBTs and AAA with greater priority than other targets.
The only upgrade for the anti-tank missiles is Heavy Missile Warhead, increasing the damage by 25%.