The Safeguard Program was a US Army anti-ballistic missile (ABM) system designed to protect the US Air Force's Minuteman ICBM silos from attack, thus preserving the US's nuclear deterrent fleet. It was intended primarily to protect against the very small Chinese ICBM fleet, limited Soviet attacks and various other limited launch scenarios. A full-scale attack by the Soviets would easily overwhelm it, a deliberate point to ensure the Soviets did not consider it a strategic threat. It was designed to allow gradual upgrades to provide similar lightweight coverage over the entire United States over time.
Safeguard was the ultimate development of an ever-changing series of designs produced by Bell Labs the started in the 1950s with the LIM-49 Nike Zeus. By 1960 it was clear that Zeus offered almost no protection against a sophisticated attack using decoys. A new design emerged, Nike-X, with the ability to defend against attacks with hundreds of warheads and thousands of decoys, but the cost of the system was enormous. Looking for alternatives, the Sentinel program offered a lightweight cover that would protect against limited attacks. Sentinel began construction in 1968 but ran into a firestorm of protest over its bases being placed in suburban areas. In March 1969, incoming president Richard Nixon announced that Sentinel would be cancelled and redirected to protect the missile farms, and that its bases would be placed well away from any civilian areas.
The debate about ABM protection of US ICBMs had been going on for over a decade when Safeguard was announced, and the arguments against such a system were well known both in the military and civilian circles. In military circles, the most basic argument against Safeguard was that adding an ABM requires the Soviets to build another ICBM to counter it, but the same is true if the US builds another ICBM instead. The Air Force was far more interested in building more of their own ICBMs than Army ABMs, and lobbied against the Army continually. In the public sphere, opinion by the late 1960s was anti-military in general, and in an era of ongoing Strategic Arms Limitation Talks the entire concept was derided as sabre rattling. Safeguard had been developed to calm opposition, but found its new deployment just as heavily opposed. Nixon pressed ahead in spite of objections and complaints about limited performance, and the reasons for doing so remain a subject of debate among historians and political commentators.