The bomb that was dropped then was a small and weak device compared to the weapons that are now in the hands of governments. If something so small and primitive could do that then the imagination struggles to cope with understanding the full impact of even one modern warhead. And there are of course tens of thousands of them.
The technology that the United States possessed in 1945 was relatively primitive. Science has moved on an enormous distance in those 70 years. The knowledge in an average physics textbook and the spread across the world of increased sophistication in electronics, physics, and rocket systems has made access to such weapons much easier to acquire. I grew up in a world where only the United States, Russia, France, the UK and China possessed the capability to kill millions of people in one afternoon. That was scary enough. We now live in a world where Pakistan and India can do this. Where Israel can do this. Where spoiled North Korean third generation eccentric dictators can do this.
In such circumstances it is easy to become paranoid and to conclude that if others can wipe out most of the population of our country in one hour then any amount of money we spend on equipping ourselves with the most sophisticated versions of the bomb is money well spent.
Like many people I see it very differently. I am not a pacifist. You only have to study the mindset of fascists and learn about how cruel people can be once they start to believe others are inferior to them. The SS couldn't be stopped by moral arguments. It is important to argue it out with fascists and terrorists and try to take on their arguments with reason but there comes a point where there is only one way of dealing with them and that is to physically take them on.
The question therefore becomes not one of whether it is justified to use force against dangerous people. The question is when and how. Which forces are the most effective ones? What weapons do you need to deal with the likely conflicts of the modern world? Which ones make you safer and which ones might actually increase your vulnerability.
I am therefore strongly opposed to Trident. Not because I love my enemies and want to achieve world peace by knitting yoghurt. I am opposed to Trident because it is ineffective and counter-productive.
Consider first the most obvious of questions. Can you actually conceive of a circumstance in which we would wish to fire this weapon? Modern warfare doesn't consist in great set piece battles between well organised states who can be intimidated by a single weapon. Modern warfare is a highly messy business where complex mixtures of people are fighting in relatively small scale but very nasty conflicts where the front line isn't clear and the people that you want to protect are mixed up with the ones that are causing the problems. What possible use could it have been to drop a nuclear bomb on Iraq or on Afghanistan? In what way would dropping one anywhere in the Middle East make anyone living in Israel or Palestine safer for any length of time? Is there even the remotest possibility that we could resolve the situation in the Ukraine by dropping nuclear bombs on Russia? Or solve the problems in Syria with nuclear explosions?
Then there is the issue of whether the actual possession of the weapons somehow helps make us secure. President Putin is a deeply unpleasant near dictator running a horrible mafia state. He peddles a narrow minded nationalistic ideology to cover up the extreme pursuit of profit at the expense of his people. I can easily see why people would want to weaken his regime.
But pointing nuclear weapons at it doesn't do this. It doesn't make us safer. It does the exact opposite. It provides Putin with exactly the justification he wants for the propaganda of paranoia that is keeping him in power. Nothing could be more helpful for him than to be able to say to the Russian people that they need to be kept safe by a strong leader because the perfidious British have extremely dangerous weapons pointing at the vulnerable mother country. Taking away the British nuclear threat would make him weaker not stronger. The real way to weaken Putin is to stop buying his oil and gas and raw materials by investing in modern low energy science and technology. His regime would soon topple if it lost the huge financial subsidies we are sending to him. And indeed the Germans seem to be recognising this with their serious efforts to free themselves from the need to buy his energy.
The weapons that are needed for modern conflicts are flexible ones. Ones that can get forces to dangerous locations with speed and help well trained, well equipped forces to make an impact. I personally believe that we should think long and hard before deciding to use those forces and be absolutely confident that that we know what why it is absolutely necessary for Britain to be fighting, what will happen after we stop and why we are sure that it will be better than what was happening before hand. In other words we need to know why it is our business to be fighting in someone else's country and when and how we are going to win. Something we never seemed to know in Afghanistan, Iraq or Libya before we deployed troops and certainly don't know in Syria.
But leaving aside whether it is sensible to fight in any individual conflict it is clear what kind of weapons modern armies actually find effective. The commanders in the field are crying out for sophisticated aircraft, tanks, mobile ground troops and aircraft carriers that can house them close to the conflict.
Spending money on Trident is therefore not just spending money on owning something that can only ever be used to inflict horrors a hundred times worse than those of Nagasaki or Hiroshima. It is spending money to strengthen our enemies. It is spending money on fighting the last war, the cold war, instead of the current one. It is not just taking resources away from schools and hospitals. It is also taking resources away from the armed forces that we might actually need to use to keep us safe. We are spending money on Trident at the same time as we are making well trained soldiers redundant and leaving ourselves without a single aircraft carrier that actually has any functioning planes.
I call that being weak and irresponsible with the defence of our country. We need to commemorate Hiroshima by scrapping Trident now not just because it is morally right but because it is the best way to keep us all safe.