The US kept quite an arsenal of nuclear bombs and missiles during the Cold War, but not everyone knows about its plans to use "backpack nukes," reports the Smithsonian via Foreign Policy. Elite troops learned to use the bombs—called B54 Special Atomic Demolition Munitions (SADMs)—in case Communists attacked US-friendly countries like former West Germany. Although heavy, SADMs could fit in a backpack and be transported by parachute-drop, scuba mission, or even on skis. The trick was setting the timer (which was unreliable) and getting far enough away before they went off (although some commanders wanted men to stay behind and protect them).
Luckily they were never used, and units trained in SADMs kept a grim sense of humor about it. "Those who were to conduct the mission were sure that whomever thought this up was using bad hemp," said an SADM team commander. But backpack nukes served a strategic need: to destroy bridges, roads, and mountain passes in case Russian forces invaded countries where they could easily overwhelm US troops. The only downside: utter devastation. As Cold War tensions faded, the US recalled SADMs from storage depots around the world and eventually retired the project in 1989. "The idea that the world came this close to the use of nuclear weapons on battlefields across the world is entirely unreal," says Business Insider. "At least we can all be thankful that cooler heads prevailed." (Read more nuclear weapons stories.)