• First, unequivocally: Nothing in this treaty restrains the United States from pursuing a robust missile defense strategy to protect our country and our allies. Don't take my word for it. Secretary of Defense Robert Gates, who was first appointed by President George W. Bush, testified that the treaty does not limit our missile defense plans. So did two other Bush appointees -- the commander of the Joint Chiefs of Staff, Adm. Mike Mullen, and the director of the Missile Defense Agency. These are highly respected military leaders. They know the treaty and they know our national security needs. Take their word for it.

• Without New START, the only arms control agreement in force between the United States and Russia is the 2002 Moscow Treaty, which the Senate approved 95-0 despite the complete absence of verification procedures. The new treaty, on the other hand, gives U.S. officials the right to conduct 18 on-the-ground inspections a year at Russian nuclear sites and requires Russia to tell us whenever a strategic weapon is moved from one base to another or into the repair shop.

• New START was never envisioned to address with tactical nuclear weapons, an area where the Russians clearly have numerical superiority. As everyone familiar with the arms control world understands and as the bipartisan Strategic Posture Commission advised, New START is an essential step toward the follow-on accord that will tackle tactical nuclear weapons. The point is simple: We don't get to tactical nukes without first ratifying this treaty on strategic weapons. By killing New START, we never get to the tricky question of tactical nuclear weapons.

• Russia may be economically less able to field as many strategic nuclear weapons as we can today, but does anyone want it to be the other way around? New START ensures that Russia will not exceed 1,550 deployed weapons in the next decade. Does anyone want more Russian nukes aimed at us or our allies? Gen. Kevin Chilton, who is directly responsible for our country's strategic nuclear deterrent, told the Committee that New START would help him do his job and that without it the Russians would not be restrained from developing a new nuclear force and we might not know what that they were doing it.

• The bomber counting rule is based on a similar one in the original START, and it reflects the system that our own military wanted then and now. In fact, it was Republican officials who invented the so-called 'bomber discount.' The attribution rule was adopted because heavy bombers are not first-strike weapons and the discount encouraged Russia to favor bombers over missiles.

• It's true that our land-based and submarine-based conventional weapons launchers would be counted under the treaty ' and the same is true for Russia. This does not restrict our program. Admiral Mullen told the Committee that the treaty limits reflect the Defense Department position and will allow us to retain a robust nuclear triad of land, sea, and air-launched weapons. The last thing we want to do here is open a loophole that would allow Russia to claim all of its missiles were conventional and then turn around and arm them with nuclear warheads at the last minute.

• Mr. Romney has failed to read the history books just as clearly as he has failed to understand the new treaty. It was the administration of President George H.W. Bush that explicitly rejected Soviet efforts to add legally binding limits on submarine-launched cruise missiles in the original START. The last thing we want would be for Russian inspectors to be crawling around our submarines to confirm that they are not carrying nuclear warheads.

This is a moment for adult leadership and bipartisan statesmanship. I'd hope that Mr. Romney would acknowledge that anyone who aspires to the most powerful office in the world should aspire to nothing less than that.