The US has has concerns about nuclear proliferation and loose nukes. It remains the only country that actually has used nukes and thought about using nukes on China, Vietnam and even Iraq.

Monday, May. 05, 2008 US Considered Nukes Against China By AP/BARRY SCHWEID

(WASHINGTON) — President Dwight D. Eisenhower overruled some of his military commanders in the summer of 1958, ordering them not to use nuclear weapons against China if communist forces blockaded the Taiwan Strait, according to declassified Air Force documents.

Eisenhower "made it clear that the Chinese would be given a warning with conventional explosives before he would authorize dropping of the deadlier ordnance" on Chinese territories, according to the documents made public by George Washington University's National Security Archive

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