SEVENTY FOUR YEARS ago today, the US dropped an atom bomb on the Japanese city of Hiroshima. Three days later it dropped another on Nagasaki. Tens of thousands died instantly and many more over the subsequent weeks and months from toxic radiation.

By the end of 1950, over 340,000 were dead as a result of the two bombs.

Nuclear weapons are still with us, with all their appalling and much-increased killing potential. Not only are all nuclear weapons states modernising their arsenals, but the advent of Donald Trump in the White House has meant a shift in nuclear policy towards “usable” nuclear weapons – and an increase in the number of scenarios in which they may be used.

Trump has also proceeded to rip up treaties that curtail or control nuclear weapons.

US withdrawal from the Iran nuclear deal has hugely increased the danger of war in the Middle East, and last week’s termination of the Intermediate-range Nuclear Forces Treaty is a dangerous and destabilising development with the potential to take us back to the worst days of the Cold War.

It unleashes the possibility not only of a spiralling nuclear arms race, but of greater numbers of US nuclear weapons coming to Europe. At a time when President Trump’s Defence Strategy ramps up hostile intent towards Russia and China, this is not good news.

Much of this is the product of a US desire to maintain its global dominance, using military might as the means to this end.

The atomic attacks on Japan were also clear examples of this drive to global supremacy. While conventional wisdom about the dropping of the atomic bomb on Japan is that it was necessary to bring about a speedy conclusion to the war, this just wasn’t true.

By the time the bomb was ready for use, Japan was ready to surrender. As General Dwight Eisenhower said, Japan was at that very moment seeking some way to surrender with minimum loss of face, and “it wasn’t necessary to hit them with that awful thing.”

So if Japan was ready to surrender, why were atomic bombs dropped on Hiroshima and Nagasaki?

A significant factor in the decision to bomb was the US’s desire to establish its dominance in the region after the war. Those planning for the postwar situation believed that this required US occupation of Japan, enabling it to dominate the Pacific region without fear of Japanese resurgence. But Japanese resurgence was no longer the US’s key strategic concern; its main concern was the Soviet Union in the postwar world, both in Asia and in Europe.

The Soviet Union was the US’s wartime ally against Germany. Ultimately their economic systems were incompatible; the US would not accept that any part of the world economy should be closed to it, and those seeking an alternative to the US economic model tended to look to the Soviet Union.

This looming antagonism was heightened by the increased power and prestige of the Soviet Union following its role in breaking the back of Germany’s military machine.

One is forced to conclude that the US wanted to demonstrate its unique military power – its possession of the atomic bomb – in order to gain political and diplomatic advantage over the Soviet Union in the postwar settlement in both Asia and Europe.

Whilst many leading US politicians, diplomats and military figures thought it unnecessary to bomb Japan, the group around the US president at the time, Harry S Truman, pressed strongly for it. Secretary of War Henry Stimson described the atom bomb as the “master card” in US diplomacy towards the Soviet Union.

By early 1945 it was clear that while the Japanese government wasn’t offering unconditional surrender, it was seeking a negotiated surrender. Its condition was that the rule of Japanese Emperor Hirohito should be maintained without loss of face.

The US leadership did not inform the Japanese that its terms were more or less acceptable because it wanted an excuse to use the bomb – to demonstrate its awesome power in a world where only the US had this weapon. Its only opportunity to do so was before the Japanese surrendered.

The Soviet Union had promised to enter the war on Japan three months after the end of the war in Europe. That day was rapidly approaching and the US had two reasons for wishing to use the bomb before this took place.

Firstly it was likely that Soviet entry into the war would trigger a Japanese surrender, thus removing any justification for using the atom bomb.

Secondly the US wished to prevent any possibility that the Soviet Union would occupy Japan while US troops were still far away.

So the US dropped the first atomic bomb on the city of Hiroshima on August 6. On August 9 the Soviet Union entered the war in Asia, as promised. Later the same day, before Japan had had time to grasp and respond to the ghastly results of the Hiroshima bomb, the US dropped a second bomb on the city of Nagasaki.

The US government got what it wanted, but at the most appalling human cost. The danger we face today is that the current US administration will once again judge nuclear use to be advantageous.

The breaking down of the decades-long rejection – by all sides – of further nuclear use is a criminal and reprehensible development, and we must be united across our movements, across society, to say “Never Again – No More Hiroshimas, No More Nagasakis.”

Kate Hudson is general secretary of the Campaign for Nuclear Disarmament.