The U.S. Army and Air Force are locked in a stalemate over which service will actually be the driving force in future battles. The air force has long claimed that air power can be the decisive factor in battles and wars, delivering so much firepower on the enemy that American ground troops will only have to go in and arrest the survivors. This means that the air force is basically running things. During the Cold War, the army never bought into this theory. At first, right after World War II, the army was willing to grant that an air force using atomic bombs probably would be able to obliterate the opposition. But then the opposition (the Soviet Union) got nukes, and the air force edge was much diminished. The fighting in Korea during the 1950s and Vietnam in the 60s further embarrassed the air force, with the bombs proving incapable to putting the infantry out of work and the president unwilling to use nukes. The air force insisted this was all because they were restrained from hitting key targets. But the air force was kept from hitting these key targets, especially those in China, because the Soviet Union threatened to "go nuclear" if we did so. So, in practical terms, the air force could not do anything it wanted and had to develop tactics that were useful, but didn't start a nuclear war.
The air force proceeded to develop a battle plan that emphasized quickly knocking out the opponents air force, followed by attacks on headquarters, supply centers, transportation (railroads, ports, tunnels, bridges, canals) targets and combat units headed for the front line. Based on past experience (most of it bad), the air force felt that if it could move fast enough, the enemy would be shocked into paralysis and the U.S. Army would be able to more quickly deal with enemy front line troops (who were now cut off from supplies and orders from higher headquarters). This was the plan used during the 1991 Gulf War. It seemed to work. But after examining the results closely, especially interviews with Iraqi prisoners and lots of officers on our side, it appeared that, at least against the Iraqis, you could dispense with weeks of bombing and just turn the ground troops loose at the same time the bombers took off.
Before there was a chance to try this faster attack plan, Afghanistan came along. Here was a campaign where less than 300 Special Forces troops, and some CIA agents, provided advice for local allies, and selected targets for smart bombs, and led to the collapse of the Taliban government within two months. The guys on the ground were indisputably in charge, with the bombers reduced to circling around overhead, waiting for someone on the ground to call for another smart bomb. It wasn't very glamorous for the pilots, as they flew above whatever anti-aircraft fire the Taliban could muster. The Special Forces were getting shot at, but they were in charge and directing a successful campaign. The air force tried to put a spin on all this to make it look like a victory for air power. The bombers played a crucial role. But it was a supporting role. The guys on the ground were running the show.
The air force has foreseen a campaign like the one fought in Afghanistan, but they saw their elite air controllers having more of a role in decision making on the ground. Never happened. The ground troops were happy to have the ground controllers (many of whom were pilots), but saw them as communicators, not tactical advisers. And, as Afghanistan demonstrated, there were times when even a lot of bombs were not enough and everyone had to do battle using M-16s and other non-USAF type weapons.
Then came 2003 and Iraq, where the American army and marine divisions were set loose at the same time the air attacks began. Actually, the air force had been taking out key communications and military targets for months, in the guise of carrying out the patrols of the "no fly zone." However, the quick advance of the coalition ground forces did prove a shock to the Iraqis, and the air force and navy warplanes were able to take out all the key enemy targets quickly. In 22 days, Baghdad was captured. Again, the air force played an important role, but mainly in dropping their bombs where the people on the ground wanted them.
The air force is still making the case that future wars will be dominated by air power, with ground troops just along to take prisoners and occupy enemy cities and bases. What the air force fails to understand is that, centuries ago, artillerymen were making similar arguments. The gunners dubbed themselves the "King of Battle" (infantry became the "Queen of Battle", so make of that what you will). But in the end, the big guns could be a big help, but they couldn't do it by themselves. It was still the infantry and tanks going in to personally convince the bad guys that they were defeated. Bombs alone didn't quite convey the right message.
The air force won't give up. Ever since becoming a separate service in 1947, the air generals have sought ways to avoid being seen as just a supporting service for the army. But unless there are some dramatic changes in the way wars are fought, the army will remain the key service. Even the U.S. Navy recognizes this, which is why the navy tolerated the growth of it's tiny Marine Corps a century ago until it became one of the most formidable ground combat forces on the planet. The navy understands that there are limits to what ships and aircraft can accomplish. Often, you have to "send in the marines" to settle a situation once and for all. For larger operations, you need an army. While death from above can be deadly and intimidating, there's nothing more compelling than a guy standing right in front of you, pointing a rifle at your head. Works every time.