Re-read your own article: Seventy percent of foreign insurgents arrested in Iraq came from Persian Gulf countries via Syria where they were provided with forged passports, an Iraqi intelligence officer said in a published report Wednesday.
Not that 70% of insurgents are foreign to Iraq. Not that 70% of all those arrested in Iraq are from outside Iraq. 70% of the foreign insurgents caught in Iraq come through Syria. its about the country they pass through to get into Iraq.
The majority of violence in Iraq is done by Iraqis. Insurgents who are generally Baathists and Sunni trying to disrupt the occupying forces and Iraqi government. Militias who fight for various factions on all sides. Death squads operating outside and within Iraqi forces such as the police, various ministries, and the military. Organized crime hijacking convoys and kidnapping people to extort money.
The foreign fighters are the smallest number of combatants in Iraq, but they are generally very effective due to their small numbers due to training and the support they receive, and they tend to target Occupation forces to the greatest extent.
Using the term insurgents to describe the foreign fighters is technically wrong as well. Military tend to use the term insurgents to describe Iraqi's fighting in the country. Foreign fighters are just that: foreign fighters, or terrorists, or terror groups.
There is a difference.