A nuclear warhead platform was a weapons delivery system developed on Earth in the mid-20th century which placed a launch platform for nuclear warhead in a sub-orbital possition above the planet. By the 23rd century the 1960s were considered a dangerous period of Earth history due to the prolifferation of such devises which, as Spock described , filled the sky with "orbiting H-bombs, the slightest mistake could have brought one down by accident, setting off a nuclear holocaust".
By 1968 powers opposing the United States of America had launched platforms, prompting the USA to launch its own multi-warhead platform (from the McKinley Rocket Base). The Aegis deemed this an unacceptabley dangerous situation, akin to the events that had previously led to the destruction of Omicron IV, and so had its Earth agents, 201 and 347 plan to destroy the platform. The agents were killed in an automobile accident before they could complete their mission and Supervisor 194, aka Gary Seven, was sent to investigate and subsequently complete their mission. Seven was initially only partially sucessful in his objective, due to the interference of the crew of USS Enterprise, which had travelled back in time on a historical observation mission. Fortunately, James T. Kirk and Spock allowed Seven to complete his mission and destroy in the device in the air, before the then out-of-control rocket it had launched in crashed. What was subsequently seen as a near-fatal accident with the warhead platform prompted a new international agreement against the use of such weapons. (TOS episode: "Assignment: Earth")
In 1971 Seven discovered evidence, originally found by Agents 201 and 347, but lost following their demise, which implicated Counter Strike in orchestrating the development of the platforms on Earth as one of their subversive plans to wipe out Humanity. (TOS comic: "We Have Met the Enemy...")