The dire threat of Iran is widely recognized to be the most serious foreign policy crisis facing the Obama administration. General Petraeus informed the Senate Committee on Armed Services in March 2010 that "the Iranian regime is the primary state-level threat to stability" in the U.S. Central Command area of responsibility, the Middle East and Central Asia, the primary region of US global concerns. The term "stability" here has its usual technical meaning: firmly under US control. In June 2010 Congress strengthened the sanctions against Iran, with even more severe penalties against foreign companies. The Obama administration has been rapidly expanding US offensive capacity in the African island of Diego Garcia, claimed by Britain, which had expelled the population so that the US could build the massive base it uses for attacks in the Central Command area. The Navy reports sending a submarine tender to the island to service nuclear-powered guided-missile submarines with Tomahawk missiles, which can carry nuclear warheads. Each submarine is reported to have the striking power of a typical carrier battle group. According to a US Navy cargo manifest obtained by the Sunday Herald (Glasgow), the substantial military equipment Obama has dispatched includes 387 "bunker busters" used for blasting hardened underground structures. Planning for these "massive ordnance penetrators," the most powerful bombs in the arsenal short of nuclear weapons, was initiated in the Bush administration, but languished. On taking office, Obama immediately accelerated the plans, and they are to be deployed several years ahead of schedule, aiming specifically at Iran.