Briefly, I wrote a short post on private military contractors late last week, and a number of smart observers asked, among them Matt Yglesias, "Why private?" Robert Kaplan does an excellent job of laying out the key points in favor of PMCs. For me, the most important advantage they have is that, as John Robb put it (I should have excerpted his post), they are scalable and contingent. When you need trigger pullers, PMCs can deliver trigger pullers: they ramp up hiring, they train personnel for the tasks at hand or find them. Most are retired military personnel, but because these are nimble organizations, they can also draw on other sources. And when you no longer need trigger pullers, at the end of a short-term military campaign, say, PMCs shed staff. The same is not true of conventional military forces. That is very valuable.

P.S.- A friend, who has met a number of PMCs in Iraq, notes that they tend to have an impressive amount of local knowledge, more than is typical of US infantrymen. This is predictable: after all, they are older, more experienced, and they make it their business to learn as much as possible about their surroundings, and they are not slowed down by a sometimes unwieldy chain-of-command that isn't always good at getting soldiers the information they need when they need it. This is not to suggest that our volunteer army is anything less than highly competent and professional, but it's no surprise that smaller, nimbler organizations are going to be better and faster at learning. And when you're dealing with a fast-moving, ever-evolving insurgency (really a collection of dozens of groups with their own agendas), this counts for a lot.

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