It has been a particularly tumultuous year for U.S.-Pakistan relations. Washington has spent much of the year trying to calm Pakistani anger over several high-profile incidents, including the killing of Osama bin Laden by U.S. Special Forces, and NATO airstrikes that left 24 Pakistani soldiers dead. But the U.S. has had its share of frustration with Pakistan's leaders, and outgoing chairman of the Joint Chiefs of Staff Adm. Mike Mullen openly accused the country's intelligence agency of supporting the Taliban and other militants. Despite the rancor, both sides say they need the other. Still, it doesn't appear relations will improve much in 2012, especially as the U.S. inches closer to withdrawing from Afghanistan.