Kyl’s decision stunned the White House, which presumed it would gain ratification of the nuclear weapons downsizing measure before January, when six Democrat seats in the Senate are taken over by newly-elected Republicans – a political imbalance that would make ratification of New START all but impossible.

“I really do appreciate the sort of last-minute efforts of the Administration to brief just on what their thinking is, but we don’t even have a plan in writing yet. So it would be a little bit premature to bring (the START treaty) up,” said Kyl.

He observed that during the final weeks of this session of the Senate and Congress – the so-called “lame duck session” immediately prior to the swearing-in of winners from last month’s elections – his colleagues will be focusing on more pressing issues such as taxes and spending, thus allowing little time for consideration of nuclear reduction issues.

Prior to his surprise announcement, Kyl was instrumental in convincing Obama to agree last Friday to add $4.1 billion to a recent spending measure to upgrade the nuclear weapons remaining in the US arsenal after New START goes into effect. This new spending, coupled with budget measures already agreed to by Obama and Congress, translates into a pledge by the Obama Administration to spend $80 billion on nuclear weapons modernization over the next 10 years.

Vice President Joe Biden, a former US senator who served as Obama’s liaison with Kyl and other key senate Republicans on this measure, said the White House had assumed – after many weeks of cross-party negotiations – that a bi-partisan agreement had been reached.

“Failure to pass the New START treaty this year would endanger our national security,” Biden warned, adding that lacking a new treaty with Moscow would leave the US with “no verification regime to track Russia’s strategic arsenal.”

Critics of New START include James Woolsey, former director of the Central Intelligence Agency, and John R. Bolton, former Undersecretary of State for arms control. They argue that amendments in the new treaty allow Russia to debate the deployment of future American missile defenses. They also worry that the new calculus in the pending treaty would count nonnuclear missiles carried aboard Navy submarines as “strategic” US assets – thus artificially constraining the allowable size of America’s nuclear arsenal.

“The question we are now asking is this: ‘Will this treaty put the United States at a disadvantage?’” Sen. Orrin Hatch, a Utah Republican, told reporters. “From my perspective, there are some indications that it will do just that.”

Vice President Biden was unmoved by these arguments: “Without ratification of this treaty, we will have no Americans on the ground to inspect Russia’s nuclear activities. There will also be less cooperation between the two nations that account for 90 percent of the world’s nuclear weapons,” said Biden.