Gaddafi transformed Libya into a new socialist state called a "Jamahiriya" ("state of the masses") in 1977. He officially adopted a symbolic role in governance but remained head of both the military and the Revolutionary Committees responsible for policing and suppressing dissent. During the 1970s and 1980s, Libya's unsuccessful border conflicts with Egypt and Chad, support for foreign militants, and alleged responsibility for the Lockerbie bombing in Scotland left it increasingly isolated on the world stage. A particularly hostile relationship developed with the United States, United Kingdom and Israel, resulting in the 1986 U.S. bombing of Libya and United Nations–imposed economic sanctions. From 1999, Gaddafi shunned pan-Arabism and encouraged rapprochement with Western nations and pan-Africanism; he was Chairperson of the African Union from 2009 to 2010. Amid the 2011 Arab Spring, protests against widespread corruption and unemployment broke out in Eastern Libya. The situation descended into civil war, in which NATO intervened militarily on the side of the anti-Gaddafist National Transitional Council (NTC). The government was overthrown and Gaddafi retreated to Sirte, only to be captured and killed by NTC militants.