Why an American-backed coup in Britain was implausible

Was the British government in the 1950s or 1960s worried that the United States might support a military coup?

Probably not: the United States lacked the kind of training influence over British officers that facilitates coups, and Britain had entrenched political ways to replace leaders.

Foreign-backed coups usually depend on deep access to another country's officer corps, often built through training relationships. The United States lacked that kind of formative influence because very few British officers trained abroad, and those who did had already completed Sandhurst. Britain's armed forces and political establishment were also tightly interconnected through their own institutions. Whatever the television drama surrounding retired senior officers, established political mechanisms offered more plausible ways to replace an unpopular leader than a foreign-sponsored junta.