Senate vote on nuclear treaty may be defining moment for Obama

Washington — The upcoming Senate vote on a U.S.-Russia nuclear arms treaty may turn out to be a defining moment for the Obama administration's foreign policy.

If he wins the support of at least two-thirds of the Senate for the New START agreement in a vote that may come as early as Tuesday, President Obama could build on the victory as he turns to a long list of foreign policy challenges — including Afghanistan, Iran, North Korea and his broader plans to limit nuclear weapons.