I grew up with nuclear civil defense drills. I was told if I saw a bright light to duck under my wooden desk. When I would visit my father in Hollywood, he had a bomb shelter at his house. It was part of our consciousness early on.

Today, nine nations together have 15,000 nuclear weapons. Each more powerful than the one that destroyed Hiroshima. Some leaders swear they will never use these weapons; some threaten to use them tomorrow. All are fallible human beings capable of making a mistake that could end the world as we know it.

I've felt for a long time that we weren't talking about this danger enough. Well, we are now. Whether it's Kim Jong Un in North Korea or Donald Trump in the White House, hardly a week goes by when we are not reading about the possibility of nuclear war.

So I was pleasantly surprised by the decision to award the Nobel Peace Prize this year to the International Campaign to Abolish Nuclear Weapons, or ICAN. The Nobel Committee said they gave the prize to the group "for its work to draw attention to the catastrophic humanitarian consequences of any use of nuclear weapons and for its ground breaking efforts to achieve a treaty-based prohibition of such weapons."

I know the leader of this peace network, Beatrice Fihn. We met last year in Geneva when I was there talking with United Nations officials and civil society groups about working more closely together on this cause. She and her colleagues are dreamers, in the best sense. They had a dream of a treaty that could ban nuclear weapons, just the way we have banned chemical weapons and biological weapons.

When we talked last year, I supported their dream, but had my doubts about their plan. Turns out, they were right. It took years of work, but they helped convince over 120 countries to gather at the United Nations and approve a nuclear ban treaty this summer. It is just the first step; none of the nuclear-armed countries agree with this ban. It is not clear how we convince them to join, or exactly how the ban would work.

The vision, however, is correct. The only way to eliminate the global nuclear danger is to eliminate all nuclear weapons. These weapons are not our greatest security, they are our greatest threat.

And it's getting worse. As the Nobel Committee said, we live in a world where the risk of nuclear weapons being used is greater than it has been for a long time. Allies of President Trump seem to agree, with one senator warning this week that his policies could set the nation "on the path to World War III."

The President, all by himself, without checking with any of his top security advisors, can launch nuclear weapons within four minutes of his command. No one can overrule him. Once launched, the missiles cannot be recalled. And he is planning to spend over one trillion dollars on new nuclear weapons.

We are lucky to have a new generation take up this fight. ICAN is one of dozens of groups that I've been proud to work with on this great crusade like Ploughshares Fund, Global Zero and the Nuclear Threat Initiative. As my fellow New Yorker, John Lennon, said, "you may think that we are dreamers, but we're not the only ones. I hope someday you'll join us."

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