Our day in Hiroshima was enlightening, but difficult.  The Peace Park and the Peace Museum are reminders of the violence that lurks in the hearts of (mostly) men, and serve as warnings about the ultimate fruits of war.

The first sight to greet Kennon and me as we entered the park was the skeleton of a multi-story building and its once-famous dome. When our atom bomb exploded 1900 feet in the air, the building’s inner structure instantly collapsed and burned, incinerating everyone inside.

I struggled to hold back tears as we made our way through the park, especially when I paused before a monument to the 6,000 children whose lives were vaporized at 8:15 a.m. on August 6, 1945. Thousands of multi-colored origami cranes made by Japanese students were bundled together around the monument.

It is one thing to read history books about World War II, and about the war-ending explosions of the world’s first two atomic weapons. Before I came here I intellectually understood the devastating force of these weapons; after all, I spent two years working in a squadron of nuclear ballistic missile submarines.

It is another thing to stand at ground zero; to listen to English translations of survivors’ stories in the hall of records; to walk through the museum and see the burned clothing and pictures of some of the 70,000 people who were killed immediately (another 30,000 died by the end of 1945, and the 5-year total of people killed by our bomb reached nearly 200,000).

The experience was much like visiting Yad Vashem, the Holocaust Museum in Jerusalem… only this time I wasn’t seeing an atrocity committed by another nation, but by my own.

I tried imagining myself in President Truman’s chair. It had been a long, brutal war, and the pressure to end it quickly without the further loss of US lives must have been overwhelming.  Perhaps I would have accepted the case for dropping this bomb; I honestly don’t know… but the second bomb in Nagasaki was inexcusable.

I left Hiroshima with the overwhelming sense that we have a moral and spiritual (and practical!) obligation to make sure that this never happens again… to truly become instruments of peace.

But what does it mean to be an instrument of peace in today’s world? One inescapable conclusion is fraught with political difficulty: total nuclear disarmament.

I wish all American leaders would come to Hiroshima and stand amidst the destruction. I wish that they would see the burned clothing, melted buildings and pictures of mutilated bodies. I wish that they would listen to survivors’ stories, visit the children’s memorial and ring the peace bell.

Then I wish that they would ask each other whether or not weapons of mass destruction, weapons that can wreak this kind of death and havoc, have any place in the US arsenal.

To me this is first a moral rather than a security issue. If we are prepared to sacrifice our moral obligations and basic human decency for security we are already lost.

But I also believe that nuclear disarmament is an essential step on the road to a secure peace, and that the first step must be ours. Only the strongest can afford to be vulnerable, and the United States cannot expect other nations to disarm unless we lead the way.

I do not make excuses for belligerent rogue states such as Iran and North Korea. But if I were sitting in their place, and the US with its huge nuclear armament declared me an enemy, I think I might try to equip my nation with the strongest possible deterrent.

According to Department of Defense records released this year, we have 5,130 active nuclear weapons, more that 800 of which are “deployed and ticking”.

So if we truly desire peace, we should commit ourselves to nuclear disarmament, as the Obama administration is trying to do in the face of Congressional opposition. And for those who think that this is a sign of weakness, remember that we possess enough conventional weapons to destroy the world several times over.

The moral and practical issue confronting the US today is a simple one: Are we going to be people of peace, people who rise above the rhetoric of fear? Or are we going to continue the legacy of Hiroshima and Nagasaki, relying on the threat of mass destruction to enforce our will on others?