United States has contingency plans to send in special forces to help "secure the Pakistani nuclear arsenal". In 2007, Lisa Curtis of The Heritage Foundation, while giving testimony before the United States House Foreign Affairs Subcommittee on Terrorism, Nonproliferation, and Trade, concluded that "preventing Pakistan's nuclear weapons and technology from falling into the hands of terrorists should be a top priority for the US." However Pakistan's government has ridiculed claims that the weapons are not secure. Diplomatic reports published in the United States diplomatic cables leak revealed US and British worries over a potential threat posed by Islamists. In February 2009 cable from Islamabad, former US Ambassador to Pakistan Anne W. Patterson said "Our major concern is not having an Islamic militant steal an entire weapon but rather the chance someone working in [Pakistani government] facilities could gradually smuggle enough material out to eventually make a weapon." A report published by The Times in early 2010 states that the United States is training an elite unit to recover Pakistani nuclear weapons or materials should they be seized by militants, possibly from within the Pakistani nuclear security organisation. This was done in the context of growing Anti-Americanism in the Pakistani Armed Forces, multiple attacks on sensitive installations over the previous 2 years and rising tensions. According to former US intelligence official Rolf Mowatt-Larssen, US concerns are justified because militants have struck at several Pakistani military facilities and bases since 2007. According to this report, the United States does not know the locations of all Pakistani nuclear sites and has been denied access to most of them. However, during a visit to Pakistan in January 2010, the US Secretary of Defense Robert M. Gates denied that the United States had plans to take over Pakistan's nuclear weapons. A study by Belfer Center for Science and International Affairs at Harvard University titled 'Securing the Bomb 2010', found that Pakistan's stockpile "faces a greater threat from Islamic extremists seeking nuclear weapons than any other nuclear stockpile on earth". According to Rolf Mowatt-Larssen, a former investigator with the CIA and the US Department of Energy there is "a greater possibility of a nuclear meltdown in Pakistan than anywhere else in the world. The region has more violent extremists than any other, the country is unstable, and its arsenal of nuclear weapons is expanding." Nuclear weapons expert David Albright author of 'Peddling Peril' has also expressed