The U.S. Army is going through yet another debate over the size of headquarters and how many are needed. In past wars (World War II, Korea, Vietnam, Iraq) it was found that more and larger army, corps and division headquarters were needed to deal with all the details and constant activity to be handled in a combat zone. In peacetime a headquarters that is large enough for wartime operations does not have much to do for all its personnel. This leads peacetime armed forces, especially American ones, to reduce headquarters size and composition in peacetime without any specific plans on how to get these headquarters quickly back into size and shape for wartime operations. Since the 1990s reformers point out that the army has undergone some fundamental reorganizations and introduced a lot of new technology that handles a lot of the quantity and quality of wartime chores a headquarters has to handle. This trend has actually been tested in the last decade and reformers believe it sets a new standard for peacetime/wartime staffing of headquarters. Not everyone agrees although some analysts also point out that in the past wartime headquarters had a higher proportion of more talented personnel and that also made a difference. It is now possible to use talented civilians and consultants to directly help combat headquarters via the use of technology, especially satellite communications.
This concept, which the U.S. began developing in the 1990s and used with increasing frequently after September 11, 2001 is called reachback. This is where some parts of a unit ordered overseas stay in the United States, and use Internet like communications capabilities to do their work from their home base. Sending fewer people overseas is a major advantage, as it means less transportation, and supply effort, is needed. Since the 1990s it has been noted that modern communications make it practical for some support units to stay behind, with no loss in effectiveness in the entire unit. Reservists make for better reachback troops, because they have to go through more additional combat training before being sent overseas. Moreover, the reservists can be taken on and off active duty, as the workload changes.
Reachback works particularly well for intelligence work and other headquarters tasks. With reachback the few intel personnel in the combat zone are mainly there to work with local counterparts and provide them with intel collected by the UAVs and other sources. For the 2015 Iraq/Syria operation, which involves several hundred manned aircraft, UAVs and several satellites, the reachback intel operation in the United States has been equally large, so that analysts can be quickly switched to the most important possible targets. Often, though, the analysts are looking at an extended (several days to weeks or more) battle area stakeout to identify who the bad guys are, where they fight from (bunkers, buildings or ruins where they place snipers or machine-guns), where they live, where they store their supplies (especially ammo and explosives) and which vehicles they use. Once the analysts believe they have the most targets they are going to find, they send the target list off to the waiting targeting analysts in the Middle East and the air strikes are carried out as quickly as possible. The bombers have their own cams (targeting pods) so they can double check for the presence of civilians (or anything else the original analysts noted). In some cases all the analyst activity back in the United States is to confirm the identity and location one major leader or a meeting of key people. This will usually be attacked by a single aircraft or UAV. The Islamic terrorists know that when several warplanes appear overhead bad stuff (on the ground) is probably about to happen.
The same analysts teams used for air strikes in Syria and Iraq are composed of people with lots of experience at this. While their recent experience may be in Afghanistan or other parts of the Middle East (Yemen, Somalia and so on) most have spent time covering Iraq operations before 2011. The important thing is these men and women have lots of experience and skill with quickly adapting to new analysis software (many major updates since 2001). All this is made possible because of reachback. The main benefit is that reachback enables a lot of troops to operate from a foreign base without being there. Many other nations are noticing.