Yesterday I took a day trip with Gen. David Petraeus – one of his frequent "battlefield circulations" – to a small farming village near the Iraqi town of Yussefiya, about 30 miles southwest of Baghdad. These kinds of excursions are generally dog-and-pony shows: day-long spin sessions that involve a fair amount of theatrics from American officers going on about how much progress has been made. (Yesterday was no exception; the climax came when the four-star general passed out soccer balls to Iraqi kids as flashbulbs flickered.) Still, I try to tag along for them when they come up; you never know when you might come across some news. And I admit I never miss the chance to ride on a Blackhawk helicopter over Iraq – which, even after dozens of trips, is still the cheapest thrill in the Middle East.

I also happened to be interested in the topic yesterday: the military's new "concerned local citizens" programs. American diplomats and officers love to talk about this new strategy of relying on local strongmen for security – "government from the ground up," as they put it. In the short term the project has produced some noteworthy results in reducing attacks on American troops. Yet in the long term it also presents some significant risks. Two weeks ago I wrote a story for the magazine that looked at the dark side of this phenomenon, which, in practice, includes the rise of dozens of American-supported warlords. Since the story appeared, a couple of things reminded me just how difficult the balancing act will be.

One of the problems for Iraqi sheikhs is that taking money from Americans opens them to accusations of being collaborators -- a serious charge in this part of the world. "They're selling their souls, and they're not respected for it," says Peter Harling, an Iraq expert at the International Crisis Group. "Their strength is temporary." That point was illustrated vividly to me the day after I finished reporting on the warlord story. I was in Tikrit and a U.S. officer had arranged for me to have dinner – the traditional Ramadan fast-breaking – with one of the Iraqi tribal leaders who was participating in the program, Sheikh Moawiya Jebara. Yet shortly before the iftar was to begin, I got word that my dinner partner would not make it. He had been assassinated that afternoon.

The second reminder came yesterday, as I rode in a Humvee in Petraeus's convoy through the farmland around Yussefiya. As we drove by, Iraqi gunmen wearing crimson headscarves and fluorescent-orange mesh vests cradled Kalashnikovs and crouched in the high grass along the side of the road. These were the "concerned local citizens" – and they looked very much like militiamen to me. As I reported in the warlord story, U.S. State Dept. officials complained that the military's "citizens" should not be allowed to carry weapons outside their homes, for fear that they would evolve into American-supported militias. The "citizens" sometimes clash with Iraqi police units, which are often stacked with sectarian loyalists. The problem is, when the "citizens" open fire, it is generally the police who are on the right side of the law – even if the police are themselves infiltrated by religious or ethnic extremists.

When our convoy stopped yesterday I asked Petraeus about the gunmen I had seen crouching by the side of the road. "They have to have weapons" outside their homes, the general insisted. "We don't arm tribes. They're already armed." Still, Petraeus told me: "This is not a place where you can go outside with a cell phone." That balancing act is one more reason the military's "concerned citizens" program is trickier than it sometimes appears from looking at casualty figures alone.