For the second time in less than two years, Saudi Arabia deployed troops beyond its borders to contain Shiite unrest in its immediate neighborhood. In late 2009, Saudi forces fought to suppress Houthi rebels in the country's Shiite borderland to the south in Yemen. This time around, a Saudi-led force, operating under the umbrella of the Gulf Cooperation Council's Peninsula Shield Force, deployed forces to the Sunni-ruled island kingdom of Bahrain to suppress Shiite unrest. The Saudi royals, highly dependent on the United States for the security of their regime, do not deploy their forces without good reason — especially when they already have their own simmering Shiite unrest to deal with in the country's oil-rich eastern region and are looking at the potential for instability in Yemen to spill into the kingdom from the south.