WASHINGTON Just two weeks after an election that left him struggling to find his way forward, President Obama has decided to confront Senate Republicans in a make-or-break battle over arms control that could be an early test of his mettle heading into the final two years of his term. He is pushing for a vote on a signature issue despite long odds, daring Republicans to block an arms-control treaty at the risk of disrupting relations with Russia and the international coalition that opposes Irans nuclear programme. If he succeeds, Obama will demonstrate strength following the midterm election debacle. If he fails, he will reinforce the perception at home and abroad that he is a weakened president. Its really high stakes, said Geoffrey Kemp, a former national security aide to President Ronald Reagan and a scholar at the Nixon Center, a research group in Washington. I would say its the biggest gamble hes taken so far, certainly on foreign policy. The House ethics committees chief counsel recommended Thursday that veteran Rep. Charles Rangel be censured for financial and fundraising misconduct as lawmakers neared closure on an embarrassing 21/2-year-long scandal. After months of quiet negotiations blew up this week, Obama on Thursday escalated ratification of the agreement, the so-called New Start treaty, into a public showdown, enlisting former Republican officials and assigning Vice President Joseph R. Biden Jr. to work on it day and night. An allied group, the American Values Network, kicked off a television and e-mail campaign. It is a national security imperative that the United States ratify the New Start treaty this year, said Obama, flanked by Henry A. Kissinger, James A. Baker III and Brent Scowcroft, all of whom served Republican presidents. There is no higher national security priority for the lame-duck session of Congress. But Obama has no clear path to approval of the treaty without Senator Jon Kyl of Arizona, the lead Republican negotiator, who declared this week that there was no time to reach agreement this year on a nuclear modernization program that he wanted as the price for ratification. The White House has only one Republican supporter, Senator Richard G. Lugar of Indiana. A survey of 14 other Senate Republicans who were considered possible supporters found none who were willing to publicly back the treaty. Ten of them said they were undecided or were waiting for the same assurances as Kyl, and four did not respond, suggesting that approval may depend on changing Kyls mind. 'Very skeptical Among those who agreed with Kyl that the issue should wait until next year was Senator Bob Corker of Tennessee, one of three Republicans to vote for the treaty in committee in September. In an interview, he said that the treaty and modernization program needed to be fully digested, fully explained and that there was no reason to rush during the lame-duck session. Im very skeptical that its the right thing to do and very skeptical that it can be done this December, he said. Moreover, 10 newly elected Republican senators who will take office in January signed a letter objecting to a lame-duck vote. Out of respect for our states voters, we believe it would be improper for the Senate to consider the New Start treaty or any other treaty in a lame-duck session, said the letter, which was released by Senator-elect Roy Blunt of Missouri. Kyl showed no signs of backing down after meeting with Senator John Kerry of Massachusetts, the Democratic chairman of the Foreign Relations Committee. But Kerry expressed hope afterward that a deal was still possible, and the White House released new details of its commitment to Kyl to spend $84 billion over the next 10 years to modernize the nations nuclear weapons programme. Because treaties require a two-thirds majority, the White House needs 67 votes. Senator-elect Mark Kirk, a Republican from Illinois, will be sworn in Nov. 29 to replace a Democrat, so the White House will need to keep all 58 remaining members of the Democratic caucus and win over nine Republicans. If it waits until next year, it will need at least 14 Republican votes because of the partys gains. Gary Samore, the top White House arms-control official, said Thursday he feared that putting off the treaty until next year would mean it could be delayed indefinitely. As a result, the United States and Russia would not resume nuclear inspections that lapsed last year, which he said would fuel distrust and lead to a greater likelihood you could get into an arms race. He also said a failure to ratify the treaty would undercut Russian support for the campaign to pressure Iran to abandon its nuclear program. To do that, we really need the Russians with us, he told a forum at the Nixon Center. And he suggested that Kyl might not get his modernization money because Democrats and conservative Republicans in the next Congress would not go along. Support for that could evaporate if the treaty is not approved, he said. Critics of the treaty have said the administration is overstating the consequences of delay and have questioned its seriousness about nuclear modernization because it provided Kyl with its latest spending proposal only last Friday. Corker and others noted that there were still no guarantees that Congress would fully finance the program. He said insisting on a vote before the next Congress creates an air of distrust. At this point, the Democratic strategy is to keep pressing for a deal with Kyl and to respond to every Republican question in an effort to minimize any pretext for opposition. Democrats would then take the treaty to the floor in December for up to seven days of debate and force Republicans to choose sides. They are banking that Kyl has been surprised that Obama is choosing to turn the issue into a public fight. At the same time, by making it a test of his presidency, Obama risks making Republicans more reluctant to hand him a victory. Senator Mitch McConnell of Kentucky, the Republican leader, has said his top priority is to deny Obama a second term. Samore described the impact in more dire terms. If we fail to act, he said, I think it will damage the US reputation as a country thats willing to lead.