The treaty President Obama and President Medvedev will sign in Prague furthers important U.S. security interests and creates better opportunities for advancing a stronger nonproliferation regime.

The most significant aspect of this treaty is its preservation of a legally binding framework for the U.S.-Russian strategic relationship. The treaty's reduction of deployed warhead and delivery vehicle numbers is modest compared with its START I predecessor in 1991, and it does not take the levels much below the SORT agreement signed by President Bush and President Putin in 2002.

But the new START does accomplish a reduction that will be monitored, inspected, and verified. The treaty will thus help preserve the ability of the United States and Russia to know what the other is doing with its strategic weapons, promote transparency, and build confidence that the strategic relationship will proceed in predictable and mutually understood ways. This is clearly in the interest of the United States.

On another level, this agreement will strengthen the case America and Russia can take to the nonproliferation table. Most observers agree that we are at a critical moment in the history of the nonproliferation treaty's existence and that its effectiveness can be eroded without a successful review conference in May.

The new START will strengthen the position of Washington and Moscow in the debate over the future of disarmament and nonproliferation. It demonstrates their commitment to reducing nuclear weapons and will strengthen President Obama's ability to promote his vision of a world without nuclear weapons.

The United States' knowledge of Russia's nuclear arsenal will be the best assurance Americans can have that our own defenses and nuclear posture are adequate to deter any threat. Moreover, in improving the prospects for progress at the upcoming NPT review conference, the treaty will support American efforts to enhance our own security by inhibiting the further spread of nuclear weapons. These objectives improve U.S. national security and the safety of the American people.