What’s left of the insurgency relies almost entirely on IEDs.

Bomb building networks have grown more sophisticated. Much of the old military ordinance was destroyed, so IEDs are no longer build out of artillery shells. IED makers use ammonium nitrate these days, which is not as reliable.

The IED makers have gotten better at disguising the mines.

American intelligence and reconnaissance efforts have been quick to discover new disguises for these weapons (with the troops quickly notified), and widespread use of jammers, has forced bomb makers to largely abandon wireless detonation. As a result, the best paid bomb makers now are those that can build bombs that look like part of the landscape. This includes casting concrete or bricks, or fabricating metal, to create a container for the bomb that turns it into an expected object. Thus bombs can be built into the walls of buildings, curbs or underpasses and bridges. The big risk with these is that it takes longer to install them, and increases the chances of being spotted.

The bomb builders are contract workers. They are not necessarily “insurgents” in a normal sense. The Insurgents offer employment and these IED makers work for the highest bidder. It’s a business transaction. The Iraqi bomb builders are turning into freelancers, like the IRA Bombers did in the 1990s.