The United States has declared that it will seek to destroy ISIL (Islamic State in Iraq and the Levant) without putting any troops on the ground in Iraq or Syria. That means no American regular troops will be sent in for offensive combat. Some will be there to help with security around the massive U.S. embassy compound, and perhaps other American facilities as well. There will also be a lot of security contractors. While these are civilians, many are veterans of the U.S. Army, Marines, Special Forces and so on. Given their civilian status, there may be a temptation to use the contractors if a lot of offensive muscle is needed. By the end of the year there will be at least 5,000 American military personnel in Iraq and even more contractors. That number is expected to grow in 2015 is needed.
Meanwhile there will be American troops in combat. These will primarily be special operations troops from the army (Special Forces, Rangers), marines, navy (SEALs) and air force (para-rescue). There will be some similar special operations troops from American allies. Britain and Australia are already in and others are expected to join, including some Moslem special operations units that worked with NATO in Afghanistan.
The U.S. Air Force will also have air control teams on the ground, although these will often work with commando units. Many American special operations troops are trained to act as ground controllers and many have experience in combat doing this. The Western nations prefer to have a Western air controller on the ground confirming what is going to be hit. But this is not absolutely necessary. Nearly all armed UAVs fire their missiles using the vidcams (with zoom) they carry. Manned aircraft (including heavy bombers) have similar capability in the form of targeting pods. These are very popular with fighter pilots, mainly because they contain FLIR (video quality night vision infrared radar) and TV cameras that enable pilots flying at 6,200 meters (20,000 feet) to clearly make out what is going on down on the ground. The pods also contain laser designators for laser guided bombs and laser range finders that enable pilots to get coordinates for JDAM (GPS guided) bombs. Some have software that can identify many military vehicles and systems automatically. The 200 kg (440 pound) pods hangs off a hard point, like a missile, bomb, or fuel tank. Pilots and bomber crews are trained to use these pods to select and hit targets from the air if there is no one on the ground to help out.
The Iraqis and Kurds have some trained air controllers. The Iraqi ones were trained to call in strikes from Iraqi warplanes armed with Hellfire missiles. The Kurdish ones have been known to work with American Special Forces teams. It’s possible some might be allowed to operate on their own. Trusting the Iraqis, with all the bribery, divided loyalties and such is still discouraged.
The commando teams (usually three to a dozen troops) will definitely be on the ground in Iraq. Syria is another matter and they might or they might not. The problem in Syria is that ISIL is not just fighting the government (Assad) troops but also most other rebel factions. ISIL is estimated to have up to 30,000 armed men in Syria and Iraq but this includes many allies (some very recent and who previously were enemies of ISIL). The core (most reliable) ISIL force is less than 10,000 armed men. Some of these guys are very effective in combat and American troops encountered some of them in Iraq earlier. The ISIL “allies” can switch sides very quickly if the Islamic terrorists gets hammered real bad. That will happen if Iraq and the Kurds use their elite (usually special operations) ground forces to go after ISIL. This tactic is no secret to many ISIL men, who are veterans of the 2004-8 terrorism campaign in Iraq and know about how such combinations quickly shattered the Taliban in late 2001 and has hurt the Taliban badly ever since.
While ISIL knows a lot about avoiding smart bombs and missiles they also know that if they are to control their new “Islamic State” (eastern Syria and western Iraq) they have to use bases and concentrate gunmen to deal with armed opposition. There is no tactic that will make ISIL immune to smart bombs under those conditions, not if they still want to control territory in their new “Islamic State.”