i've made a scenario WW2:
AI build missiles units (cruiser & nuclear) but don't use it !
even if i copy/paste the missiles slots of the original Civ2 Rules.txt
Missile (air unit): only attack ships. if 'destroy after attack' flag is on, it will attack any ship with load or attack strength (i.e., will not attack empty transport); if the flag is off, it works like a fighter; if make it a land unit, it works like a land unit.