Hiroshima horror a reminder of why mankind must work towards the elimination of nuclear weapons

The nuclear era began 70 years ago with the dropping by the US of atomic bombs on the Japanese cities of Hiroshima and Nagasaki. Not before or since have such weapons been used against civilians; the results were so instant and horrific that no government has since dared. But in the wake of the devastation, with imperial Japan having surrendered and admitting defeat, came the knowledge that possession of the technology and arms meant power. Nine governments now have them in the belief that they are a deterrence and provide security, but the more that are acquired, the greater the chance they can be misused.

North Korea's nuclear programme, as much to deter as threaten, proves the point. It is why the world worked so hard to strike a deal with Iran; allowing it to be in a position to develop atomic weapons would have caused even greater instability to the Middle East. A single bomb can, after all, exact a horrific toll. In an instant, perhaps 140,000 lives were wiped out in Hiroshima and three days later, another 70,000 at Nagasaki, while tens of thousands more in time died from radiation and untold more were physically and mentally scarred for life.

There is an argument that because nuclear weapons are so destructive, they will never be deployed. But governments have several times contemplated just that, as did the US and Soviet Union during the Cuban missile crisis in 1962. Accidents can happen, as miscalculations have shown with nations preparing to launch strikes. Stockpiles not properly secured can be stolen by extremists, who could also hack into computer systems.

Japanese survivors are in the forefront of efforts to prevent a nuclear war. But as they lobby, Prime Minister Shinzo Abe is fast-tracking through the upper house of parliament the final stages of a revision of the nation's famous pacifist constitution to allow troops to fight abroad for the first time since the war. A majority of the nation's people reject the change, fearing remilitarisation will deepen wounds with neighbours, particularly China and the Koreas, that have yet to heal.

Abe's speech on August 15, the 70th anniversary of Japan's surrender, will be closely watched for how far he is willing to go with an apology for Japanese wartime aggression. There is no doubt that he should be forthcoming. But in a similar vein, the world's nuclear powers should use the commemoration of the atomic bombings for a policy shift. They need to be more determined in working together for nuclear disarmament.