Al-Qaeda became a household name after the suicide attacks on New York and Washington on 11 September 2001. But the jihadist network goes back to the late 1980s, when Osama bin Laden and other mujahadeen fighting the Soviet army in Afghanistan formed 'the base' (al-Qaeda). This new group sought to 'cleanse' Muslim countries of Western influence, topple 'corrupt' regimes and establish a pan-Islamic caliphate. Starting with training camps in Sudan and attacks in Somalia, it graduated to embassy bombings in Kenya, an attack on the USS Cole in Yemen and 9/11. Groups associated with Osama bin Laden's organisation have often been blamed for subsequent attacks, such as the bombing of a train in Madrid in 2004, or for insurgent activity in Iraq after the 2003 US-led invasion. However, al-Qaeda is as much an ideology as it is an organisation; often it is nothing more than a loose network of local Islamist terror groups acting on their own initiative. So its 'involvement' in an attack may range from direct training and assistance to an imitation of its methods or mere inspiration. The 2001 invasion of Afghanistan after 9/11 led to the defeat of the Taliban and forced the al-Qaeda leadership it had been hosting further into hiding. As the US has renewed the pressure in Afghanistan and Pakistan with Predator drone attacks recently, militants have increasingly found new havens and training grounds in Yemen, Somalia and Africa's Sahel region. Several attempts to hit the West in 2009 failed, but put al-Qaeda back into the headlines. Al-Qaeda suffered a major setback when its founder and leader Osama bin Laden was killed by US Navy Seals in the Pakistani city of Abbottabad in May 2011.