At a U.S.-Russian summit in Prague, President Barack Obama and Russian President Dmitry Medvedev signed a new Strategic Arms Reduction Treaty, dubbed the New START, to cut their nuclear arsenals by a third.
"As I said last year in Prague, this treaty will set the stage for further cuts. And going forward, we hope to pursue discussions with Russia on reducing both our strategic and tactical weapons, including non-deployed weapons," Mr. Obama said.
The signing of the treaty, which must still be ratified by the Senate, comes ahead of next week's nuclear security summit in Washington, D.C., which will be attended by more than 40 heads of state.
We went to several analysts to get their perspectives on START, asking them: What is the significance of the treaty, and is it in the United States' best interest? Here's what they said:
National security research fellow at the Heritage Foundation
"New START is more of a distraction than a help in addressing the strategic dangers facing the U.S. and its allies.
"The Nuclear Posture Review, correctly, identifies the dangers posed by nuclear-armed terrorism and nuclear proliferation as the most pressing. Yet the Obama administration chose to focus on concluding a new Cold War-style arms control agreement with Russia. It argues that the conclusion of New START will show the world that the U.S. is leading by example -- fulfilling the president's vision for a nuke-free world, and serving to bolster the counter-terrorism and nonproliferation regimes.
"But this outcome is far from certain. In fact, it borders on fantasy to expect that Iran and North Korea, for example, will be so impressed by the new treaty that they abandon their nuclear programs.
"It is highly unlikely that New START will benefit U.S. interests. In a world where nuclear terrorism and proliferation are the primary concerns, the U.S. should be pursuing a more defensive strategic posture. New START won't help advance a defensive strategic posture for the U.S. or other states. It could even undermine this purpose. After all, it encourages Russia to adopt a more threatening posture toward the U.S. based on its strategic nuclear force.
"Further, there is the possibility that New START will contain a number of technical problems. Areas of concern include the accounting rules, verification, enforcement and whether the U.S. will have the kind of modernized strategic nuclear arsenal it needs under the numerical restrictions imposed by the treaty.
"From a defensive point of view, this treaty is truly a bad START."
Director of the Proliferation Prevention Program at the Center for Strategic and International Studies
"The START treaty is significant on several levels. First, it locks in a 30 percent reduction in deployed strategic nuclear warheads and limits strategic delivery vehicles to 700 deployed and 800 total. While these limits are not deep reductions, and in fact the limits on delivery vehicles would likely have been met anyway, it's important to make legally binding ceilings while we can.
"Second, this treaty contains verification measures which had lapsed with the expiration of START I. Verification measures are important to build confidence and enhanced transparency. Consultations with the Russians on verification was one of the few avenues for dialogue in past years.
"Third, this new START treaty is a key element in resetting U.S.-Russian relations which had been at an historic low point.
"Fourth, this new START treaty is a positive indication of U.S. and Russian commitment to steps toward disarmament. This commitment is critical to winning support for urgent nonproliferation measures elsewhere.
"This particular treaty is a down payment on further deep reductions in nuclear arsenals that may be possible not only with Russia but other states. Even though Russian nuclear weapons no longer pose the devastating threat of destruction they once posed, it is still important for strategic stability to reduce nuclear weapons in tandem. This agreement does not require changes in the U.S. strategic triad. Nor does it curtail missile defense deployments. It does not degrade U.S. nuclear deterrent capabilities in any way. More importantly, it allows the United States to regain its leadership role on arms control, disarmament, and nonproliferation issues."
Director of the Russia and Eurasia Program at the Carnegie Endowment for International Peace
"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."