Monday and Tuesday, President Obama hosted leaders from 46 other countries at a summit on nuclear weapons, focused on the threat of terrorists getting nuclear material. It ended with an agreement that each country would take measures to protect nuclear material used in bombs, civilian reactors, and power plants, and work together to reinforce international efforts.
The summit was the latest effort in what news reports are calling Obama's "nuclear spring," a broad initiative to revive U.S. arms-control efforts and elevate the role of international treaties in U.S. nuclear weapons policy. John Isaacs of the Council for a Livable World summed up the spring so far:
Stepping back from the past few frantic days on nuclear weapons issues, it is useful to realize how much has been accomplished. The last two weeks have arguably been the two most eventful weeks on reducing the dangers posed by nuclear weapons since the advent of the nuclear age.