In other words, the US doesn’t like launching over habitable land. PR isn’t very good if you drop a booster on someone or if a rocket blows up over land. The Russians and the Chinese don’t have such qualms.
When the Germans began actually launching IRBM’s (the V-2) they lost 2/3 to 3/4 of the rockets at low altitude, off course, immediate engine destruction.
By the time we began launching our own rockets and engines (Redstone, Vanguard, Atlas, Titan, Jupiter, Explorer, Atlas-Centaur, and the hundreds of sounding rockets from Wallops Island, Lake Superior, Alaska, etc.) the loss rate got down to 1/5 to 1/3 - after a few years of 2/3 to 3/4 losses. Yeah - NASA and the US government was very reluctant to shoot many large rockets from anywhere but the huge ranges out west: Edwards, Nevada, and El Paso/White Sands.
The comparative loss rate of NASA’s Gemini-Titan and Saturn I/II/IIB and Saturn 5 were unheard of by anybody worldwide.
Many years ago SAC actually set up a test launch of a Minuteman from an operational Launch Facility, LF, but it failed.
The safety requirements for isolating the test LF and the test Launch Control Centers made it impossible for the missile to properly receive the commands needed to launch while ensuring none of the other 49 missiles saw the commands.