The Afghanistan war of the 21st century began when the global terrorist organization, al Qaeda, attacked the United States on September 11, 2001. At that time, al Qaeda's main bases were located in Afghanistan, under the auspices of the Taliban government, then in control of much of the country. Since the attack (known as 9/11), the United States has led an international coalition of allied nations to secure a peaceful, terrorist-free Afghanistan as part of its ongoing effort to combat terrorism worldwide. This conflict traces its roots in the Cold War. The Soviet Union militarily intervened in Afghanistan in 1979–1989 to secure a communist government on its border. The United States supported anti-communist insurgents at the time, some of whom later joined the Taliban or otherwise turned against the United States and its allies after the Soviets withdrew, which ultimately led to the attack of September 11, 2001.