Relations with the US and other Western countries have been further strained by the perception that Saudi Arabia has been a source of Islamist terrorist activity, not just internally, but also world-wide. Osama bin Laden and 15 out of the 19 September 11 attacks hijackers were Saudi nationals, though some officials argue that this was planned deliberately by bin Laden in an attempt to strain U.S.-Saudi relations, and former Central Intelligence Agency director James Woolsey described Saudi Arabian Wahhabism as the soil in which al-Qaeda and its sister terrorist organizations are flourishing. Some in the U.S. Government also believe that the royal family, through its long and close relations with Wahhabi clerics, had laid the groundwork for the growth of militant groups like al-Qaeda and that after the attacks had done little to help track the militants or prevent future atrocities.