Going back in time, the U.S. government inadvertently created al Qaeda by encouraging, funding, and arming radical Islamist fighters against the Soviet Union in faraway Afghanistan during the 1980s. After the 9/11 attacks by that group, the U.S. government, by conducting an unrelated invasion of Iraq, then unintentionally created an even more brutal group called al Qaeda in Iraq, which pledged allegiance to the main al Qaeda group in Pakistan, and eventually morphed into the even more vicious ISIS. ISIS then took over large parts of Iraq and Syria, but began to attack Western targets only after a U.S.-led coalition began bombing the group in those countries.

Directly planned attacks by ISIS have occurred in Europe, but ISIS has had problems recruiting people in the United States to go to Syria for military training and return to the United States to attack, because its Muslim community has not been radicalized. Thus, the group has had to rely often on spontaneous and crude — but nevertheless sometimes deadly — attacks by relative amateurs "inspired" by the group, such as the incidents in San Bernardino and Orlando.