Since Saudi Arabia houses the holiest sites in Islam ( Mecca and Medina ) , many Muslims were upset at the permanent military presence . The continued presence of US troops after the Gulf War in Saudi Arabia was one of the stated motivations behind the September 11th attacks and the Khobar Towers bombing . Further , the date chosen for the 1998 United States embassy bombings ( August 7 ) was eight years to the day that American troops were sent to Saudi Arabia . Bin Laden interpreted Muhammad as banning the " permanent presence of infidels in Arabia "
Khobar Towers bombing
Khobar Towers bombing
Motives for the September 11 attacks