ON Monday this week, the Foreign Ministers of the G7 countries made a historic visit to Hiroshima in Japan.

Appearing alongside the UK’s foreign secretary Philip Hammond, John Kerry became the first US secretary of state to visit the city’s Peace Memorial Park, where he laid flowers at the cenotaph commemorating the 140,000 victims of the atomic bomb dropped on the city by the US military at the end of the Second World War.

In the past three years serving as the USA’s senior international representative, John Kerry has undoubtedly been a witness to tragedy in all its shapes and forms across the world. He’s visited war zones and has no doubt seen the brutal aftermath of conflict in the many ways it manifests itself.

But his evocative personal description of his visit to the Peace Memorial Museum deserves to be shared more widely. He said: “It is a stunning display. It is a gut-wrenching display. It tugs at all of your sensibilities as a human being.

“It reminds everybody of the extraordinary complexity of choices in war and of what war does to people, to communities, to countries, to the world.

“This was a display that I will personally never forget. I don’t see how anyone could forget the images, the evidence, and the recreations of what happened on August 6 1945.”

In my experience in Parliament, MPs and others often talk about serious political issues like this in an intangible way.

Many have placed the debate around whether to renew the UK’s own Trident nuclear weapons system in financial or economic terms.

For example, I’ve heard MPs use figures calculated by CND to argue against renewal. These statistics suggest that the total cost of Trident renewal, including the procurement and maintenance of the new missiles, has now risen to a phenomenal £182 billion.

Others have highlighted the hundreds of jobs which are supposedly reliant on pursuing this military strategy, while opponents have countered this argument with contrary statistics combined with plans to retrain workers in order that their skills can be used in other ways to support our peace efforts.

There are also sound arguments that possessing weapons of mass destruction is the wrong strategic choice in safeguarding our nation’s future, and that the Government’s focus should be on pursuing more effective methods of defence given the new and emerging security threats we face.

These are all valid and factually sound points. But for me, John Kerry’s comments from Japan highlight the fundamental issue.

Nuclear weapons are designed to end the lives of huge numbers of people.

The single bomb dropped on Hiroshima over 70 years ago killed as many people as live in the city of Dundee, laid utter waste to an area the size of Glasgow city centre and tore the roof from buildings over four miles from the epicentre of the explosion.

Today’s technology means that the power of the modern equivalents to the bomb that flattened Hiroshima far exceed even this horrific toll.

We must anchor the debate about the UK’s ownership of nuclear weapons in an ethical and moral debate, not just a financial or economic one. Those of us who believe that Scotland and the UK should take a different path when protecting our future need to reflect on the lessons from Hiroshima and the enormous and horrendous impact these armaments had on the population there.

We must not forget.

The Labour Government’s illegal actions in Iraq under Tony Blair’s premiership have discredited the concept of an ethical foreign policy for many, but I believe that it’s not only still possible, but absolutely essential to protect our future security at home and abroad.

We need to frame our discussions on Scotland and the UK’s place in the world in terms of the social impact of our policies and actions.

We need to be clear about the human impact of the choices that we make, not just the economic ones.

It is not morally acceptable to justify Trident renewal or the sale of UK arms to Saudi Arabia with the full knowledge that they are being used illegally in the conflict in Yemen in order to line the pockets of those at the top of our arms industry.

We must use our leverage with our international allies and friends to promote peace and the advancement of human rights, not just to trade in arms.

In the weeks and months to come, Parliament will have some fundamental decisions to take on these issues.

When I cast my vote in the lobby of the House of Commons, I’ll be remembering the thousands of victims of weapons of mass destruction wherever they have been, and making my personal commitment not to repeat the tragedy of Hiroshima.