Many of the American military advisers who are heading to Baghdad will be doing a detailed assessment of the army’s needs, American officials say.

But a measure of the military’s desperation is that its chief assistance now comes from hundreds of thousands of volunteers and a smaller number of highly trained militia members. For army units — and there are a number of them — that are fighting hard, often under difficult circumstances, adding volunteers who have little or no experience has been of questionable benefit. Hundreds of volunteers have been killed or wounded in ambushes on their way to the battlefield, for example. That is not true of the trained militias, which have far fewer fighters but are experienced and highly trained, mostly by the Iranians, and who augment the regular army’s morale, said commanders.

Strengthening Iraq’s air assets would also seem to be a necessity. Earlier this year, the military had just three Cessna aircraft able to deliver American-made Hellfire missiles, but recently the army was down to two aircraft and was running out of missiles, officials said.

One bright spot, officials say, is Iraq’s elite counterterrorism force, which the United States has been quietly training at the Baghdad airport. Yet since the withdrawal of American troops at the end of 2011, the skills of Iraqi forces have atrophied, American officials said. The Iraqi military is not practiced at maneuvering on the battlefield and has become a “checkpoint army,” a force that is adept at checking identification but not at taking the fight to its enemy, Western officials said.

From the point of view of Iraqi Amy officers, they are in a desperate situation: ill-equipped against an enemy they say they were not trained to fight.

“We don’t have enough intelligence information, we don’t have good air coverage, we are battling very well-trained groups that have good experience in street fights, that are moving fast between cities and villages,” said one commander in Salahuddin.