Not a professional historian but I know a little bit about the subject.

The Atomic bombs dropped on Hiroshima and Nagasaki were recognised as a game changer internationally. This was the first time that a weapon was capable of literally obliterating an entire city and noone learnt this more severely than the Japanese who surrendered after Nagasaki, fearing more attacks of the same nature.

Following the parting of the ways of the Grand Alliance after their victory in Berlin, the world eventually descended into Cold War. Out of Russia, England and the US; only Russian maintained its wartime leader as Churchill had been ousted in a surprise win by the Labour Party and Roosevelt was succeeded by Truman.

Divided by ideology of the best way to organise Europe, the nuclear arms race between the US and USSR was on. The Soviets tested their first atomic bomb in 1949 but were far behind the ground made by the US. Their bombs were primitive in comparison and they had far less of them too.

In 1950, Stalin, bolstered by China's recent communist revolution, gave the green light for North Korea to invade South Korea. Stalin was quite surprised at the speed that the US jumped to defend the south. This war is where we first really see the effects of nuclear weapons.

The US monopoly of atomic bombs was over, but the Soviet's arsenal and capability still could not compare. Atomic bombs were not used during the Korean War, despite the US being backed into many corners but the most telling part is this little known fact...

Late in the war, US and Soviet pilots came into direct conflict with each other yet neither side announced that this had happened. Both sides tacitly understood that to avoid the Cold War heating up, they could not be seen to actually fight with each other. This is the effect that nuclear weapons had, they held each to a stalemate.

in 1953, Stalin died and was succeeded by Nikita Khrushchev who adopted a potemkin strategy, vastly over exaggerating Soviet's nuclear capabilities - though it is difficult to say if this actually had any effect on the West. Eisenhower came into office in the US and a year later the US tested their first hydrogen bomb - BRAVO.

The test was unprecedented. Instead of 6 megatons as expected, BRAVO blew with 15 megatons of radioactive force setting off Geiger counters across the planet and killing a Japanese fisherman aboard a ship.

What is fascinating about this test is that observers from both the US and the USSR all commented similar things about it; it was terrifying and almost certainly could never be used.

Eisenhower began his presidency seeing nuclear weapons as comparable to any other weapon he had seen during his time in WWII: to be employed and used to win at all costs. BRAVO completely shattered his own view.

So in short, the answer to your question is yes; nuclear weapons were always seen as having the capability to change the nature of war. There's a reason that Japan 1945 was the first and last time that they were used. The weapons are so indiscriminately destructive, so final, and carry with it assured destruction for both sides that they dwarf any other actions of war by default.