The 2015 Iran nuclear agreement was a triumph of diplomacy and a victory for global security at a time when the whole world is threatened by the proliferation of nuclear weapons that could have catastrophic consequences for humankind and our precious environment.

President Trump’s decision to withdraw from the deal is a major setback for international cooperation, global peace building and the long-term goal of a world without nuclear weapons, articulated by leaders from Ronald Reagan to Barack Obama.

As co-founder and co-chair of the Nuclear Threat Initiative, I am both saddened and angered by this reckless decision. I look forward to the day when the United States regains its place as a global leader, providing vision and actions to eliminate nuclear threats.