Missile Defence

There are two dead safe methods to survive a nuclear attack with ICBMs. Defence with anti missiles and "Duck and Cover" where a simple desk will defy a multi megaton nuke. Your mission is to protect six major cities against a global nuclear attack, else perish with them. You control three anti ICBM missile launch sites, if you run out of missiles or all your launch sites are destroyed you are out of luck until the end of the stage.