Andrew Tarantola
The plan was simple: mount a nuclear ICBM atop a truck, then spread a bunch of them (and hundreds of decoys) out along Nevada and Utah to create a fully-mobile counterpoint to any Soviet first strike. So why did America's Midgetman program never get off the ground?
All the nukes in America's arsenal wouldn't have done us a lick of good had the Soviets knocked them offline during a preemptive first strike. That's why the US government went to such great pains defending the weapons—typically storing them in armored subterranean silos. There were limitations to this plan, of course, as silos are only useful until they're spotted. Once the enemy knows a silo's location, it can easily be bombarded into oblivion. But should that silo be sitting on two axles, it can be moved from location to location as the situation dictates. So between 1986 and 1992, that's exactly what the US Air Force tried to do—with spectacularly unsuccessful results.
The effort was essentially a response to the development of the Soviet S-24 and S-25 mobile ICBM launchers—the former ran on railroads, the latter on paved roads—which could easily be repositioned out of harm's way in the event of attack. The US program originally aimed to make their stock of LGM-118 MX Peacekeeper and LGM-30 Minuteman ICBMs more mobile. However, the size of these weapons—each about 60 feet long, weighing 38,000 pounds, and containing up to 10 nuclear-tipped reentry vehicles—made transporting them across America's highways nearly impossible.
As such, the Air Force went about developing a smaller version: the 14-foot, 30,000-pound Small Intercontinental Ballistic Missile (SICBM) or MGM-135A Midgetman. It was small enough to travel on unmodified civilian roadways yet still powerful enough to ruin Moscow's week from the other side of the Pacific. Each missile packed a 475 kt nuclear warhead and could travel up to 6,800 miles using internal GPS guidance.
https://gizmodo.com/why-the-lgm-135a-midgetman-was-americas-shortest-lived-1657920701
