Al Qaeda, Cohorts Remain Worst Terror Threat: U.S.

After the September 11 attacks, al Qaeda remains the biggest terrorist threat to the United States and its allies.

Al Qaeda "utilizes terrorism, as well as subversion, propaganda, and open warfare; it seeks weapons of mass destruction in order to inflict the maximum possible damage on anyone who stands in its way, including other Muslims and/or elders, women and children," said the report.