Negotiators from the P5+1 and Iran have agreed to extend the talks on Iran’s nuclear program to June 2015. Many issues are still to be solved, such as establishing a formula for verifiably limiting Iran’s uranium enrichment capacity as well as an acceptable process for relieving sanctions. Still, all parties to the talks have stressed the need to reach a comprehensive agreement.

The recent election of Hassan Rouhani as president of Iran provides a new and important opening for the United States and its P5+1 partners to secure an agreement that limits Iran's nuclear capabilities in exchange for easing tough international sanctions.

In May 2010, nearly 190 nations will meet in New York to assess the implementation of the Nuclear Non-Proliferation Treaty (NPT) and to chart a path forward for progress on its three pillars: nonproliferation, disarmament and peaceful uses of nuclear energy.

Experts discussed the key technical and policy developments relating to the CTBT over the past decade, including the maintenance of the U.S. arsenal in the absence of testing and capabilities to detect and deter nuclear test explosions.

(The following op-ed by Daryl Kimball, executive director of the Arms Control Association, first appeared in Defense News on March 5, 2007.)

Following the end of U.S. nuclear testing a decade and a half ago, some scientists and policy-makers worried that the reliability of U.S. nuclear warheads could diminish as their plutonium cores age. They claimed it would take a decade or more to see if the nation’s weapon laboratories could maintain the existing stockpile of well-tested but aging weapons without further nuclear blasts.

Such concerns led many senators to withhold their support for ratification of the Comprehensive Test Ban Treaty (CTBT) in 1999.

Time has addressed the skeptics’ concerns. For more than a decade, a multibillion-dollar Stockpile Stewardship program has successfully maintained the existing U.S. nuclear arsenal in the absence of testing. As the importance of nuclear weapons in U.S. military strategy has diminished, there has been no need to test new types of nukes.

But now, the Bush administration is asking Congress to fund an ambitious effort to build new replacement warheads, which it claims is needed to avoid plutonium aging problems that could reduce weapon reliability. (Read More)

Two former U.S. secretaries of defense, a former U.S. secretary of state, and twenty other nonproliferation experts released a statement today urging all governments to recommit themselves to their obligations under the nuclear Nonproliferation Treaty (NPT) as a bulwark against proliferation.