This is when the army and air force realized they had never practiced this sort of thing before. Oh, both the army and air force had written manuals full of procedures on large scale operations, and how you should handle dozens of controllers occupying the same combat zone. But no one had actually tried it out, even in practice. It was a disaster in Afghanistan, with large loss of life (to friendly fire) avoided by luck, and the direct intervention of officers in the headquarters, and on the battlefield. For the next few years, the army and air force scrambled to overcome decades of indifference and lack of training.
Everyone agreed that the only long term solution was more training between air force and army units. This was easier done by the army than by the air force. Getting aircraft into the air was very expensive (over $8,000 an hour per plane), and the air force had lots of other things it wanted to train for (air-to-air, long range bombing, electronic warfare and so on). The army also wanted to train its own people as air controllers, something the air force eventually compromised on. The air force would allow army people to be trained as controllers, but the air force would do the training. The problem with that is, the air force hasnt got the training capacity for that. With 700 controllers (joint tactical air controllers, or JTACs) currently, and rushing to expand that to 1,100, there isnt much room for army trainees.
But increasing the number of controllers (the army wanted, for starters, one per company, or at least nine per brigade) brought with it problems of control. With that many controllers, several of them might be called on to hit the same target on a typical battlefield. So the army and air force had to develop a new system, to cut out the duplication. This was done largely by changing the procedures, especially at headquarters, to keep track of who was calling in fire for what target on what piece of real estate.
Meanwhile, the army has come up with the JFO (Joint Fires Officer) concept. These guys would be able to call in artillery (both army and naval gunfire) as well as army helicopters gunships, and select targets for the bombers (which would be passed to air force controllers to get bomber overhead to do the deed). The air force agrees with the army that, eventually, every platoon or squad will have someone equipped and qualified to call in bombs and missiles. Technology, more than training, will most likely make this possible. Meanwhile, the air force is having no trouble getting volunteers for JTAC duty. In the past, pilots avoided a tour as a JTAC. But now theres a war on, and most JTACs can expect to see some action. Most pilots arent picky in that respect, fighting hostiles on the ground or in the air is all the same as long as it's real. The air force sees a long term benefit in this. Over the next two decades, some of the JTACs will become generals, and when they have to work with their army counterparts, they will have an easier time of it because they have participated in ground combat.
Since late 2001, the U.S. Army and Air Force have had a rather loud wake-up call on how to deal with close air support (CAS). When September 11, 2001 rolled around, the army had pretty much written off the increasingly feeble air force efforts at providing air support. The army had beefed up its artillery and helicopter firepower over the previous two decades, and was ready for the air force to eventually get rid of the A-10, and further cut back training of pilots for CAS. But in Afghanistan, during late 2001 and early 2002, the army found itself fighting without access to helicopter gunships or artillery. Air power was all it had. That worked pretty good, at first, for three reasons. The army troops involved were Special Forces, who had air force controllers (to talk to the bombers overhead) who were well trained, and numerous. Second, there was the new smart bomb, the JDAM, that used GPS for navigation. This was a breakthrough weapon that was receiving its first, and very successful, heavy use in combat. Finally, there were new gadgets (laser range finder binoculars and the PRC-117 satellite radio) that made it much easier for the controllers on the ground to get the needed information for the pilots, and quickly get it to the pilots. This combination proved a spectacular success. But then other army troops arrived, with more air controllers, and more headquarters (with more air force staff officers to supervise all those controllers and warplanes.) This created problems.