One of the emerging memes of the past couple of weeks is a slow resignation to the fact that, whatever the American people want, Washington will not reduce troop levels in Iraq below 100,000 for the indefinite future. If casualties are down, some argue, Americans will buckle under and hang in there for the duration. For what? Some glimmer of normalcy somewhere down the road. No one likes to admit defeat or futility - especially after so much money, so many lives, so much human wreckage. But here's one factor that needs to be placed into this equation as well: even the best-run occupation will have constant casualties. Yesterday, several Iraqi civilians were killed in incidents that are understandable if obviously awful. Vehicles that don't stop as ordered; a sudden flare of violence; a fallible soldier under insane stress: mistakes happen, innocents die, resentments build. Sure: Arabs seem to be able to generate resentments regardless of cause. But occupying a Muslim country for ever is not, it seems to me, a way to reduce tensions between Islam and the West, to defang the appeal of Islamism, to erase the notion that the US in Iraq is now indistinguishable from Israel in the West Bank in the Arab mind. Maybe this is a price we have to pay to save face and avoid wider catastrophe. But it is a price. And, as time goes by, more and more people will pay it.