Republican presidential front-runner Mitt Romney cruised to victory in the Nevada caucuses Saturday night, notching a second consecutive triumph against a field of rivals suddenly struggling to keep pace. (Today)

A U.N. Security Council effort to end the violence in Syria ended in acrimony and a veto by Russia and China on Saturday, hours after the Syrian military attacked the ravaged city of Homs in what opposition leaders described as the bloodiest government assault in the nearly 11-month-old uprising. (Today)

MOSCOW -- Tens of thousands of Russians embraced the numbing cold and marched to a frozen river bank near the Kremlin on Saturday, demonstrating their determination to keep up the pressure on Vladimir Putin for fair elections and honest government. (Today)

TEHRAN, Iran -- Iran began ground military exercises Saturday and defiantly warned that it could cut off oil exports to "hostile" European nations as tensions rise over suggestions that military strikes are an increasing possibility if sanctions fail to rein in the Islamic Republic's nuclear program. (Today)

WASHINGTON -- The United States' plan to wind down its combat role in Afghanistan a year earlier than expected relies on shifting responsibility to Special Operations forces that hunt insurgent leaders and train local troops, according to senior Pentagon officials and military officers. These forces could remain in the country well after the NATO mission ends in late 2014. (Today)