Not sure if this AFP news report (15 July 2007) has been noted here:

Most foreign fighters and suicide bombers in Iraq come from Saudi Arabia, despite attempts by US officials to portray Syria and Iran as the main culprits of violence, a US newspaper reported Sunday.

Citing an unnamed senior US military officer and Iraqi lawmakers, the Los Angeles Times newspaper said about 45 percent of all foreign militants targeting US troops and Iraqi security forces were from Saudi Arabia, 15 percent from Syria and Lebanon, and 10 percent from North Africa
RJO