Al-Qaeda has attacked civilian and military targets in various countries. For example, it carried out the September 11 attacks, 1998 US embassy bombings and the 2002 Bali bombings. The US government responded to the September 11 attacks by launching the War on Terror. With the loss of key leaders, culminating in the death of Osama bin Laden, al-Qaeda's operations have devolved from actions that were controlled from the top-down, to actions by franchise associated groups, to actions of lone wolf operators. With the death of key communicators, like Anwar al-Awlaki, the ability of al-Qaeda's "brand" to inspire, motivate and instill fear has sharply declined.
Characteristic techniques employed by Al-Qaeda include suicide attacks and simultaneous bombings of different targets. Activities ascribed to it may involve members of the movement, who have taken a pledge of loyalty to Osama bin Laden, or the much more numerous "Al-Qaeda-linked" individuals who have undergone training in one of its camps in Afghanistan, Pakistan, Iraq or Sudan, but who have not taken any pledge. Al-Qaeda ideologues envision a complete break from all foreign influences in Muslim countries, and the creation of a new world-wide Islamic caliphate. Among the beliefs ascribed to Al-Qaeda members is the conviction that a Christian–Jewish alliance is conspiring to destroy Islam. As Salafist jihadists, they believe that the killing of civilians is religiously sanctioned, and they ignore any aspect of religious scripture which might be interpreted as forbidding the murder of civilians and internecine fighting. Al-Qaeda also opposes man-made laws, and wants to replace them with a strict form of sharia law.
Al-Qaeda is also responsible for instigating sectarian violence among Muslims. Al-Qaeda is intolerant of non-Sunni branches of Islam and denounces them by means of excommunications called "takfir". Al-Qaeda leaders regard liberal Muslims, Shias, Sufis, Ahmadiyyas and other sects as heretics and have attacked their mosques and gatherings. Examples of sectarian attacks include the Yazidi community bombings, the Sadr City bombings, the Ashoura Massacre and the April 2007 Baghdad bombings.