The New Strategic Arms Reduction Treaty (START) has won ratification in the U.S. Senate, passing by a 71-26 vote. Ratification is a victory for President Barack Obama, those who seek a world with fewer nuclear threats as well as proponents of a constructive U.S.-Russia relationship.

New START was agreed to earlier this year — months behind schedule — and was signed by Mr. Obama and his Russian counterpart, President Dmitry Medvedev, in April. The treaty replaces the 1991 Strategic Arms Reduction Treaty, and limits each country to 1,550 deployed nuclear warheads (a reduction from 2,200 under an earlier agreement) and 800 strategic delivery vehicles. Approval by the Senate was delayed as U.S. politics descended into midterm turmoil and as Republican senators flexed their new muscle after the shellacking they administered to the Democrats in the November ballot.

The treaty enjoyed support from all senior members of the U.S. military establishment, as well as distinguished foreign policy experts and former officials. Nonetheless, serving Republicans were reluctant to endorse New START. Objections ranged from the spurious — insufficient time and attention given to discussion and debate — to the serious — whether the treaty might in some way limit U.S. freedom of maneuver regarding missile defense deployments and whether the U.S. nuclear infrastructure is being sufficiently maintained.