Graham Allison, director, Belfer Center for Science and International Affairs, Harvard Kennedy School

We should applaud President Obama for shining the spotlight again on nuclear danger. Amidst the swirl of urgent issues pressing upon his agenda, he demonstrates a great capacity to remember what is important.

The aspirations he articulated demand international attention. If these are to be achieved, the administration will now have to shape specific strategies and plans of action for each.

Those of us who follow these issues should not be shy in offering our best ideas about how these ambitions can become accomplishments. If and as they do so, we will all live in a safer world.