The U.S. Army is studying its experience in Iraq and Afghanistan, looking for ways it could have done things better. Army commanders have, since the 1970s, been trained to study history, and look for useful lessons there. Right now, the army is looking for quicker and cheaper ways to handle terrorist hideouts like Iraq and Afghanistan. The current solutions have been used for centuries, but are expensive. Even though the U.S. substantially reduced the American casualty rate in Iraq and Afghanistan (compared to Vietnam), there are nearly 40,000 wounded and lots of stress (PTSD) injuries.
In both countries, the U.S. encountered a corrupt and inefficient culture that was fragmented into mutually hostile groups. That's nothing new. The first European colonists in what would become the United States found a patchwork of mutually hostile, unreliable and unpredictable tribes. But the Europeans, and later Canadians/Americans/Mexicans had an advantage in that they were there to stay. That made imposing order over the long term a lot easier. But in later peacekeeping operations, like the Philippines (ten years of intense operations, and several more decades of occupation), Haiti (20 years), South Korea and Vietnam, it all depended on the locals, and if the locals could not get their act together, instability could persist for a long time. Haiti has been a mess for over two centuries, and two decades of American occupation was only a temporary fix. Vietnam was corrupt and divided, but by the time North Vietnam launched its successful invasion in 1975, South Vietnam was more united than it had ever been. South Korea has similar corruption problems when U.S. troops came in to eject the Japanese in 1945. The U.S. removed most of its troops (except for trainers) by 1950, North Korea then invaded, and after a three year war, was expelled and kept out. But it took South Korea another three decades to get their economic and political act together. American troops were there throughout, but always restricted to base when there was political unrest outside. It was the South Koreans who eventually cleaned up their own mess.
Currently, the U.S. military is involved with five countries (Iraq, Pakistan, Afghanistan, Yemen, and Somalia) that Islamic terrorists are trying to use as bases. In all cases, the United States followed its standard (since the 19th century) playbook. Go in, overthrow the bad guys, find some locals who are willing to set up a better government, and help them do it. That isn't working so well in these five countries. The corruption and local animosities keep getting in the way. The U.S. (and the rest of the world) has given up on Somalia. Iraq has all that oil money, and has to be watched to insure that another Saddam does not take control, and invite all the terrorists back in. Yemen has the oil rich Gulf Arabs, especially a neighbor like Saudi Arabia, constantly involved. But even local Arab nations find themselves frustrated at the corruption and factionalism in Yemen.
The U.S., Afghanistan and India find themselves equally perplexed trying to deal with Pakistan. This is a country where most of the population fears foreign invasion, oblivious of the fact that the country is such a mess, that no one wants to invade. Maybe help to prevent Islamic terrorists from setting up shop, yes. But move in? No way.
Iraq was a clear victory, although remnants of the corrupt and cruel Sunni Arab (Saddam/Baath Party) government fights on, promoting the bloody fantasy that they can terrorize their way back into power. But the majority Shia/Kurd government, while democratic, may be no more successful than Haiti. The corruption and misrule is common throughout the Arab world, and no nation has provided a democratic example that works. The West is mainly concerned with Iraq not going back to being a supporter of international terrorism. But even that's not a sure thing.
One of the plans put forward in the U.S. Army is the greater use of trainers, especially culturally adept ones like Special Forces operatives. But these guys are always in short supply, and many are leaving the army because of family stress (spending most of their time overseas.) However, the military is taking heart from the success of the multi (State Department, Defense Department, Agriculture Department, etc) Provincial Reconstruction Teams (PRTs). But these operations often survived due to the efforts of larger American military units in the area, and have a limited supply of adequate recruits. The big problem is corruption, which involves not just local officials, but every aspect of the local culture. This is a big problem, and no one has come up with a quick fix. If they army has one, they are not talking about it. So they probably don't.