U.S.," the American intelligence official said. Foreign participants When Saddam Hussein was captured in December 2003, several documents were found in his possession. One particular document, which was apparently written after he lost power, appeared to be a directive to his Ba'athist loyalists warning them to be wary of Islamist mujahideen and other foreign Arabs entering the country to join the insurgency. The directive supposedly shows Saddam having concerns that foreign fighters would not share the same objectives as Ba'ath loyalists (i.e. the eventual return of Saddam to power and the restoration of his regime). A U.S. official commenting on the document stressed that while Saddam urged his followers to be cautious in their dealings with other Arab fighters, he did not order them to avoid contact or rule out co-operation. Bruce Hoffman, a Washington counter-terrorism expert stated that the existence of the document underscores the fact that "this is an insurgency cut of many different cloths...[and] everybody's jockeying for their position of power in the future Iraq." Many experts believe that fighters from other countries who have flocked to Iraq to join the insurgents are motivated by animosity toward the United States and the desire to install an Islamic state in place of the Ba'ath Party's secular regime. Foreign fighters are mostly Arabs from neighboring countries, who have entered Iraq, primarily through the porous desert borders of Syria and Saudi Arabia, to assist the Iraqi insurgency. Many of these fighters are Wahhabi fundamentalists who see Iraq as the new "field of jihad" in the battle against U.S. forces. It is generally believed that most are freelance fighters, but a few members of Al-Qaeda and the related group Ansar al-Islam are suspected of infiltrating into the Sunni areas of Iraq through the mountainous northeastern border with Iran. The United States and its allies point to Jordanian-born Al-Qaeda in Iraq leader Abu Musab al-Zarqawi as the key player in this group. Zarqawi was considered the head of an insurgent group called Al-Tawhid Wal-Jihad ("Monotheism and Holy War") until his death on 7 June 2006, which according to U.S. estimates numbers in the low hundreds. Usage of the term "foreign fighters" has received criticism as being Western-centric because, taken literally, the term would encompass all non-Iraqi forces, including Coalition forces. Zarqawi has taken to taunting the American forces about the irony of the term: "Who is the foreigner, O cross worshippers? You