There isn't a single substantiated fact in anything you've said. The "fly-trap" scenario you've described is nothing more than a lame attempt to explain (and provide a retroactive justification) how the U.S. could possibly find itself fighting a guerrilla war and incurring heavy casualties more than two years after "major combat operations" supposedly end. You will not find a single U.S. military source that ever used this rationale before the war began, mainly for two reasons: 1) the war wasn't supposed to last this long, and 2) they never expected to find so many foreign forces involved in Iraq.
Iraq in the long term view is a battle in the War against Radical Islamicism. That war was always expected to take a long time, the length of any particular battle is fairly irrelevant. We are involved in battles with Syrians, Iranians, Saudis, and Pakistanis, and more in Iraq. Because we are fighting them in Iraq now, those eventual battles will be easier and may require less actual warfare when they are fought because their most committed fighters lie dead in Iraq.
2) they never expected to find so many foreign forces involved in Iraq.
This is a war, we can't control how the enemy chooses to fight back. They could have stayed hidden in their home countries and waited till we left a free stable Iraq before choosing to go in and take over in five years. THe fact that they have chosen to take a strong position in a sure to lose Iraq battle is theirs to make.