The presidents of the United States and of Russia have signed the New Strategic Arms Reduction Treaty, or START, which authorizes significant reductions of the nuclear weapons and delivery systems of both countries.

President Obama signed a nuclear arms control agreement — the New START treaty — with Russian counterpart Dmitry Medvedev in Prague in April to much fanfare. Senate hearings on the treaty are taking place.

Senator Richard G. Lugar, one of the Republican Party’s senior voices on foreign affairs, fired back Thursday at Mitt Romney over his opposition to the new nuclear treaty with Russia, accusing Mr. Romney of “hyperbolic” rhetoric that is divorced from the reality of arms control.

Mitt Romney’s criticism of the New Strategic Arms Reduction Treaty (New START) ["Obama's worst foreign mistake," op-ed, July 6] raises several concerns about the agreement and its impact.

Even in these polarized times, anyone seeking the presidency should know that the security of the United States is too important to be treated as fodder for political posturing.

When I worked as assistant secretary of defense for Ronald Reagan, the president demonstrated two particularly important characteristics.

The Nobel Prize committee may have been easily swayed by President Obama’s quest for a world free of nuclear weapons, but getting the Senate to actually cut the U.S. nuclear arsenal looks to be a far tougher sell. Still, word on the Hill is that the New START treaty got a surprise boost last week.

Russian President Dmitry Medvedev on Friday said he had submitted a landmark nuclear arms reduction treaty with the United States to the lower house of parliament for ratification.

The Pentagon has now told the public, for the first time, precisely how many nuclear weapons the United States has in its arsenal: 5,113. That is exactly 4,802 more than we need.

The officials say the New START treaty doesn’t solve all nuclear issues between Moscow and Washington, but it would pay dividends by showing the United States’ commitment.