"This is one of those rare times in the United States Senate where we have it within our power to safeguard or endanger humankind," Sen. John Kerry, D-Mass, Foreign Relations Committee chairman and one of the floor debate managers, said ahead of the vote. "The question is whether we will move the world a little more out of the dark shadow " of nuclear uncertainty,
Sen. Dick Lugar, R-Ind., the ranking Republican on the committee, noted bipartisan consensus from military and diplomatic leaders under several presidents for the ratification of the new Strategic Arms Reduction Treaty.
Rejection of such consensus "would be an extraordinary action for this body to take," Lugar said.
"We have the chance today to not only approve new START treaty" but also reach consensus on reaching national security goals, the senator said. "I am most hopeful the Senate will embrace the opportunity to bolster our national security."
Vice President Joe Biden sat as Senate president during the ratification vote on the treaty signed April 8 by President Barack Obama and Russian President Dmitry Medvedev.
Opponents objected on a number of fronts, from timing of consideration to saying the United States came up with the short end of the stick in negotiations.
Sen. Mark Kirk, R-Ill., called the treaty "ill-advised," while urging the administration to "devote time and attention" to ending Iran's nuclear program instead of the "laudable (and) modest" treaty.
Johnny Isakson, R-Ga., said he was voting for the treaty, which needed bipartisan support to reach the required two-thirds majority, saying America "will be strong in our strength and we will trust but we will verify."
The world was watching, Kerry said, to see whether the United States "as stewards of enormously destructive power now would be stewards of peace."