The answer: American troops will be replaced by American airpower.
Veteran investigative ace Seymour M. Hersh addresses some troubling questions surrounding that probability in a New Yorker article.
Quick, deadly strikes by U.S. warplanes are seen as a way to improve dramatically the combat capability of even the weakest Iraqi combat units. The danger, military experts have told me, is that, while the number of American casualties would decrease as ground troops are withdrawn, the over-all level of violence and the number of Iraqi fatalities would increase unless there are stringent controls over who bombs what.
* * *
Within the military, the prospect of using air power as a substitute for American troops on the ground has caused great unease. For one thing, Air Force commanders, in particular, have deep-seated objections to the possibility that Iraqis eventually will be responsible for target selection. “Will the Iraqis call in air strikes in order to snuff rivals, or other warlords, or to snuff members of your own sect and blame someone else?” . . . a senior military commander now on assignment to the Pentagon asked. “Will some Iraqis be targeting on behalf of Al Qaeda, or the insurgency, or the Iranians?”
* * * *
The insurgency operates mainly in crowded urban areas, and Air Force warplanes rely on sophisticated, laser-guided bombs to avoid civilian casualties. These bombs home in on targets that must be “painted,” or illuminated, by laser beams directed by ground units. “The pilot doesn’t identify the target as seen in the pre-brief” – the instructions provided before takeoff – a former high-level intelligence official told me. “The guy with the laser is the targeteer. Not the pilot. Often you get a ‘hot-read’” – from a military unit on the ground – and you drop your bombs with no communication with the guys on the ground. You don’t want to break radio silence. The people on the ground are calling in targets that the pilots can’t verify.” He added, “And we’re going to turn this process over to the Iraqis?”Well, let’s hope not.
Recall that replacing boot power with air power didn’t work in Vietnam, where unlike the Iraqi Army, the ARVN (Army of the Republic of Vietnam) was not beset with ethnic rivalries and had trained alongside American ground and air troops for years.
There are no best-case scenarios here: Don't expect air power to work in Iraq, either.