The United States is having a major problem getting its own bureaucrats to work together while trying to rebuild Iraq and Afghanistan. Peacekeeping is all about helping war ravaged nations rebuild themselves. No one likes doing it, as it's a thankless task. The same problems that caused the war in the first place, are usually still there to torment peacekeepers and those helping with the "nation building."
There are other problems as well. What is going on now with most American nation building efforts is basically bureaucracy in action. When the Department of Defense decided "nation building" wasn't its trade, the State Department got the job, and quickly fobbed it off on USAID (U.S. Agency for International Development, an independent agency.) Unfortunately, USAID is not a major player in the U.S. government, and has constantly run into problems with Department of Defense or State Department bureaucrats still demanding a say in the effort (but not wanting any of the responsibility). Everyone complains about the resulting inefficiency, but no one seems capable of doing anything about it.
The current military "solution" to this problem is the PRT (Provincial Reconstruction Team.) The PRTs evolved from the JRTs (Joint Reconstruction Teams) established by U.S. Army Special Forces in 2002. Thirteen PRTs are run by U.S. and coalition troops, with nine operated by NATO forces. The core element of a typical PRTs has 83 people. This includes 79 military personnel and three civilians, plus an Afghan minister of the interior police officer. American PRTs are commanded by army lieutenant colonel, who is actually leading two civil affairs teams, an Army Reserve military police unit, plus intelligence and psychological operations teams. The civilians usually consist of officials from the State Department, USAID, and the U.S. Department of Agriculture. The rest of the troops are assigned to security duties, which can be pretty tense in areas where Taliban gunmen are operating, but is basically police work (against bandits and unruly warlord militias) elsewhere. These security troops often end up assisting in reconstruction as well. The Afghans have been urging the expansion of the PRT system, not just to get more reconstruction expertise to all areas of the country, but to provide some protection for reconstruction staff (including the many NGOs that are not a part of the PRT system.)
PRTs have had some success, but they have not been able to cut through the bureaucratic roadblocks created by different Department of Defense, State Department and USAID agendas. The State Department, when told to send people to work with PRTs, provided very junior folks, with little experience in anything. The Department of Defense has people there to provide security and is, technically, not involved in nation building. But the troops can take over in an emergency, because they are, after all, in charge of security. But in active areas like Iraq and Afghanistan, the military is really running the show. Combat needs come first, and everything else, including nation building, is support. When it comes to nation building, the Department of Defense wants power, but not responsibility. Same thing with the State Department, and neither Defense or State wants to take orders from USAID.
Good things are still accomplished. There's always a list of things accomplished, whenever someone back in Washington asks how the nation building is going. But there are an increasing number of complaints coming in as well, about opportunities missed because of bureaucratic turf battles and trying to avoid responsibility.