The American public is asking a fundamental question: Will the New START Treaty increase U.S. national security and reduce nuclear threats?

We began working together to reduce the threat of nuclear weapons in the 1980s, when the Cold War created a threatening environment that could lead to an all-out nuclear war between the United States and the Soviet Union. It was a very real possibility.

Today, the nuclear threat has changed. The possibility of nuclear war has declined, but the chances of nuclear weapons being used by a terrorist group, or a rogue nation in a regional war, are increasing. These threats are fueled by the spread of nuclear weapons, materials and technology around the world.

With this new context, the goal of nuclear threat reduction grows ever more vital to U.S. security. After we reviewed the treaty and the testimony presented by experts, we now believe the American public can, with confidence, support this agreement.

It is likely to improve the security of the United States, and our allies, and lead to even greater international cooperation on nuclear risk reduction. The long, careful process to produce this treaty should increase cooperation on missile defense capabilities, which can provide an important measure of protection against an actual attack, or an accidental firing.

The New START treaty is relatively straightforward: The treaty sets lower ceilings on deployed strategic nuclear warheads and long-range ballistic missiles and bombers, with important provisions to verify the new terms. In our view, this represents a crucial step forward in reducing the nuclear threat.

We find three important reasons for support:

First, with the expiration of the 1991 START Treaty last December, there is no longer any agreement for monitoring strategic nuclear forces on both sides. The treaty’s provisions for data exchange and on-site inspection is likely to provide valuable information on Russian nuclear capabilities that we would not have otherwise. It is also likely to increase transparency and confidence on both sides — improving predictability, stability and security.

Second, New START reaffirms the long-standing principle of achieving greater nuclear reductions in the two nations that still control more than 90 percent of global nuclear inventories. This principle underpins our nonproliferation diplomacy worldwide, and helps open the door to even greater cooperation with other nations on the most pressing nuclear threat issues, including nuclear terrorism and the nuclear programs of Iran and North Korea. Going forward, Washington and Moscow must increase our work together to further reduce nuclear threats.

Third, Washington and Moscow should expand use of the existing Nuclear Risk Reduction Centers – which we, and other members of Congress, established with President Ronald Reagan to further reduce nuclear threats.

For example, to improve both nations’ early warning capabilities, the centers could exchange data on global missile launches. Other nations could be integrated into this system. It could provide the basis for a joint initiative involving Russia, the United States and the North Atlantic Treaty Organization on a missile defense architecture for Europe that would help address other key issues, like tactical nuclear weapons vulnerable to theft by terrorists. Indeed, when the centers were proposed, they were envisioned to help prevent catastrophic nuclear terrorism. These initiatives can go forward with a New START Treaty.

Together, we have spent more than 50 years in the Senate working on national security issues, and our confidence in our nation’s treaty ratification process now leads us to urge the America public to support the New START Treaty.

Critics have expressed understandable concerns that the treaty might undermine the U.S. missile defense program, citing the preamble language on the relationship between strategic offensive and defensive arms; or the treaty’s prohibition on using existing strategic launchers for placement of missile defense interceptors, or Russian assertions of a right to withdraw.

There have also been legitimate issues raised about the importance of a strong U.S. commitment to maintaining the safety, security and reliability of our own weapons, given the treaty’s reductions and the continuing need for a strong nuclear deterrent in light of today’s threats.

The defense secretary, the leaders of the Joint Chiefs of Staff, and the general in charge of our missile defense program have all testified that New START is not a threat to U.S. missile defenses. Their statements are an important step in addressing the missile defense issue, as is the administration’s proposed 10-year nuclear stockpile plan.

These are important issues that must now be considered under our constitutional process and monitored in the years to come by the executive and legislative branches so that the treaty will merit broad and sustained bipartisan support.

The American public can be confident that this treaty enhances our national security.