IN the last few days people across the world have been marking the anniversary of an event which all of us have a duty never to forget.

70 years ago this month, atomic bombs were dropped on Hiroshima and Nagasaki, killing hundreds of thousands of people.

Some were literally vaporized in an instant, leaving nothing but their shadow burned into the pavement. Others died soon afterwards as a result of horrific burns. Many more took weeks, months or even years to die as radiation and related diseases took their toll.

There are really no words which adequately describe the destructive power of nuclear weapons, and Japan is the only nation on earth that knows first-hand the devastating human consequences.

I’m pretty sure many of us would never have heard the names Hiroshima or Nagasaki were it not for the events of 70 years ago, which have now become such a core part of the identity of these places – but just as important a part of that identity is a strong and lasting commitment to nuclear non-proliferation.

And this really came across in images we saw on TV of the dignified memorial services taking place in both cities this week. The people of Hiroshima and Nagasaki are determined that no one else in the world should ever suffer the same fate that they did.

But I was also struck by the sheer number of towns and cities across the entire world who joined them to mark this anniversary – including around two dozen events right here in Scotland organized by the Campaign for Nuclear Disarmament.

For all of my adult life I have been against nuclear weapons – indeed, I was in the CND before I joined the SNP back in the 1980s.

And although the world has changed much since then, the arguments used to justify nuclear weapons are exactly the same: essentially that the world is a very dangerous place, and we don’t know what rogue regimes might threaten us in future.

But the obvious response to this is also unchanged: the world is a much more dangerous place because of nuclear weapons. And we will never be certain what threats face us in future – but we can be pretty certain that nuclear weapons won’t protect us from them.

In this parliamentary session, the Westminster Parliament faces a key vote on whether to replace Trident and spend £100bn on a new generation of nuclear weapons, which sit just 30 miles from Glasgow on the Clyde.

It seems hard to believe, but each one of the warheads used on Trident is eight times as powerful as the bomb dropped on Hiroshima. Each missile contains three warheads. And each submarine carries up to 16 missiles.

It is truly disturbing to reflect on the scale of suffering and devastation that nuclear weapons can bring. Above all else, to avoid the use of such weapons in the future—whether by accident or by design—we must commit ourselves to ridding the world of their presence. We must do that through words and through deeds.

The SNP’s landslide election win in this year’s General election gives Scotland a much stronger voice at Westminster, and I am proud that the new block of SNP MPs have made such a strong start in the House of Commons - forcing the Tory Government to retreat on issues like scrapping the Human Rights Act and repealing the ban on Fox Hunting in England.

It just shows you what a concerted and determined opposition can achieve.

On nuclear weapons, the voice of Scotland’s MPs could not be clearer – 57 of the 59 MPs are opposed to the renewal of Trident. Only the solitary Lib Dem and Tory MPs intend to vote in favour.

The debate on Trident renewal will be one of the central debates in the House of Commons this session.

But it is a debate which cannot be left to politicians alone – everyone who believes in a nuclear-free world must make sure that their voices are heard loudly and clearly.

So as we contemplate what happened in a faraway country 70 years ago this month, we should never forget that the debate over nuclear weapons is not some abstract political discussion.

It is about how we want to define ourselves – both at home and abroad.

And I hope that, when we come to mark 75 years since the atomic bombings, we can show the people of Hiroshima and Nagasaki that we stand with them as proud advocates and practitioners of the cause of nuclear disarmament.