I think you are misreading the situation. Back in that time period, several science fiction writers assumed that Abombs would be used regularly in war - that the barrier was between Abombs and Hbombs, not between conventional bombs and Abombs.
Very, very weird to a modern eye, but there you are.
Generally, opinion may well be 'what's the point of having the weapons if you can't use them, that's just stupid'. This is LONG before MAD, after all.
Uh, he was talking about America's *global* standing. The science fiction writers you are thinking of were probably American (and hardly necessarily representative of American public opinion anyway).
I think a better way of measuring world opinion, at least for democratic countries, are election results and the opinions of elected leaders. Attlee made a frantic trip to the US because of some remarks made by Truman which were probably meant as boilerplate but which Attlee interpreted as meaning that the US might use nuclear weapon in Korea.
https://books.google.com/books?id=GqT3AgAAQBAJ&pg=PT186 (The reputation he wrongly got for having dissuaded the US from such a rash move no doubt helped him in the 1951 campaign even if it wasn't quite enough to give Labour a plurality of the parliamentary seats). In Europe even without the US use of nuclear weapons, millions of people supported the Communist-sponsored "peace" movement. In France in 1951 the Communists got over 26 percent of the vote. In Italy, in 1953 the Communist party and the then-pro-Communist Nenni Socialists got a combined 35.3 percent of the vote in 1953.
https://en.wikipedia.org/wiki/Italian_general_election,_1953 The US using nuclear weapons might be a good way to getting those figures up to over 50 percent....
US policy makers were well aware of the horror of world opinion on the US use of a-bombs and especially on the effects on Asian opinion of using the bomb on Asians for the second time within a decade: "Reports followed from Third World officials suggesting that the United States was “willingto use mass destruction methods on Asians but not on Europeans.”30 From US embassies around the world, US diplomats warned that use of the bomb in non-Soviet Asia would create waves of “horror and antipathy.”31 The reaction in India, leader of the non-aligned countries, to Truman’s statement on the atomic bomb was overwhelmingly negative. Prime Minister Jawaharlal Nehru was “vehemently
denouncing any suggestion of use of atomic weapons,” while the Indian representative at the UN emphasized a widespread feeling in Asia that “the atomic bomb is a weapon used only against Asiatics.”
Nor would reactions be any more favorable in Europe and elsewhere: "But the public horror of atomic weapons presented a serious political obstacle. State Department studies suggested that foreign governments and peoples would strongly oppose the use of atomic weapons.21 The bomb had come to have a special horrifying status. A planner in the State Department’s Bureau of Far East Affairs warned in November 1950 that even though 'the military results achieved by atomic bombardment may be identical to those attained by conventional weapons, the effect on world opinion will be vastly different. The A-bomb has the status of a peculiar monster conceived by American cunning, and its use by us, in whatever situation, would be exploited to our serious detriment.'” In the UK, Attlee was not the only leader to view the prospect with disfavor: "When Winston Churchill became prime minister the following year, he was adamant that no atomic bombs be used in Korea or on China"
"The State Department followed public opinion closely, reporting in the months after Truman’s infamous press conference in November 1950 that European public opinion on atomic weapons was generally negative. In strong language, the report described the attitude in France as one of “a general public repugnance to use of the weapon under any but the most dire circumstances.'" :
All these quotes are form Nina Tannerwald, *The Nuclear Taboo* available online at
http://blogs.unpad.ac.id/desyamaliayusri/files/2012/05/The-Nuclear-taboo.pdf Tannerwald in fact thinks that unfavorable world opinion, especially from US allies, may have been a bigger factor in the non-use of nuclear weapons than fear of Soviet involvement.