Check out The Web of Terror as depicted by the Center for Strategic and International Studies (CSIS) in the London Times.

Note the roles of nationals from various countries. The innocuousness of the claims against Syria stands out. (I will put online shortly a CSIS working draft by Anthony Cordesman which contains a number of interesting comments on the role of Syria.)

Saudi Arabia

Some 350 Saudis suspected of joining al-Zarqawi in Iraq. Some have already returned to carry out terrorist attacks.

Egypt

Some 300 Egyptians thought to have gone to Iraq to fight for al-Zarqawi.

Jordan

Al-Zarqawi's homeland and main area of operations outside Iraq. 59 killed in suicide bombings last week in Amman. Accomplices still at large.

Algeria

Provides an estimated 600 volunteers for operations in Iraq; the largest component in al-Zarqawi's force.

Syria

Main transit point for fighters and funds. Al-Zarqawi thought to have visited the country on several occasions.