One of the issues we need to face next month is the growing cost to the West of staying in Iraq. This is not just the financial burden, which is immense, or the loss of life and limb, which knows no price. It's the cost of engaging - but not defeating - the terrorist enemy with one of the smartest, most high-tech militaries the world has ever known. To survive, the terrorists and insurgents and militias need to keep improvising their tactics, honing their skills and constantly improving their equipment. These skills and devices are transferable from Iraq across the globe. We may, in other words, be giving Jihadists the best training they have ever had, without obliterating them. Newsweek reported the following a week ago. It deserves wider airing:

About two years ago, Americans fighting against Shiite insurgents began seeing the deadly effects of a new IED, with a charge that could blast right through an armored vehicle, even a tank. These explosively formed projectiles (EFPs) are shot out of crude cannons shaped roughly like coffee cans. Making an EFP requires expertise and machine tools, and earlier this year the Americans claimed the devices originated in Iran. The military claims that EFPs accounted for a third of American combat deaths in July. The success of the insurgent tactics employed in Iraq seems to guarantee we will see them again elsewhere.

In the dry jargon of military thinkers, guerrilla fighting is called "asymmetrical warfare." The asymmetries are not just physical or technological, but moral. Martin Van Creveld, a well- respected historian at Hebrew University, puts the proposition starkly: because occupying powers are automatically cast as the bully, they have to show restraint in the battle for world opinion. "You cannot be both strong and morally right at the same time," says Van Creveld. "But if you are small and weak, then you can do whatever you want. Necessity does not have any moral bounds."

They have a serious advantage in targeting us. And we are now helping them develop their skills and weapons in ways Osama bin Laden could once only dream of. The fruits of Iraq may well be felt one day on the streets of Chicago or Houston.

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