[From the back of the box (US PC edition)]
Counterstrike, the exciting companion disk to the best-selling Command & Conquer Red Alert, is full of clandestine activity, experimental technologies and disavowed tactics. Now you decide the ultimate fate of the struggle between the Allies and the Soviets.
Of course, you can't have the battle without the war. You must own Command & Conquer Red Alert to play this missions disk.