Despite a venerable tradition under Republican presidents of successfully negotiated and ratified nuclear arms control agreements (Nixon in 1972, Bush I in 1992 and Bush II in 2003) some conservative voices, among them presidential hopeful Mitt Romney, Arizona Senator John Kyl and the Heritage Foundation, have voiced reservations about the treaty. In the meantime, most Senate Republicans, with the notable exception of Senator Lugar (Ind.) who supports the treaty, have withheld any comment.

The ominous silence of the Republicans is unfortunate because the New START treaty deserves unqualified, bi-partisan support and prompt implementation for three critical reasons. First, if ratified, it will provide for the continued predictability of force structures on both sides. Without agreed limits on nuclear arsenals the United States and Russia would be forced to worst-case the future, over-compensate for unknowns, and unnerve each another by even modest adjustments to their strategic forces. At home, a world without New START would condemn the administration and Congress to endless wrangling over the appropriate force size, budget priorities, and strategy.

A second reason that New START is vital to the US is that it will provide for continued transparency of Russian nuclear activities and infrastructure. Because neither side has complete confidence in the other, both the United States and Russia have designed an extensive verification regime. Through national technical means (i.e. satellites, radar, etc.), formal data exchanges and on-site inspections (which ended last year and will not resume unless New START is ratified), the two countries closely monitor each other’s installations and activities to verify compliance and reveal unauthorized activity. Transparency is key to maintaining confidence in the arms control process and eventually moving to even lower levels of nuclear weaponry.

Finally, New START is critical if the United States hopes to maintain a pivotal leadership role in controlling, reducing and perhaps even eliminating nuclear weapons worldwide. While drawing down US strategic nuclear forces will not guarantee that other nations will abandon their efforts to obtain nuclear weapons, refusing to constrain US forces will certainly guarantee that other nations will view the US as purely self-serving and more easily disregard any US efforts to limit their own nuclear options. After all, if the United States isn’t prepared to restrain its nuclear ambitions, why should Iran or North Korea or, for that matter, Japan or Germany?

When the New START agreement comes up for a vote, in committee and on the Senate floor, the debate should not be over whether 1550 strategic nuclear warheads is the correct number to maintain deterrence or whether $11 billion is enough to maintain the nation’s nuclear stockpile. The real issue is whether the United States is better off ratifying a New START treaty that will provide for a predictable and transparent relationship with Russia or abandoning efforts to scale back the threat of nuclear weapons and living in a world without limits. The New Start treaty deserves the support of those Senators who have not yet declared themselves.

Jack Mendelsohn, a former Senior Foreign Service Officer, was a member of the US delegations to the SALT II and START I negotiations and the former Deputy Director of the Arms Control Association.