President Trump should chose a strategy with a clear, limited goal: shore up the Afghanistan government, help it gain greater legitimacy and strengthen its security forces. The point is not some kind of flashy victory but avoiding a terrible defeat. Achieving stability in Afghanistan is worth a modest commitment of U.S. troops, Special Operations forces and air power. A major surge of the size that President Barack Obama approved early in his first term is not being discussed. The point is to show the Taliban that it can’t topple the central government, and coax the Taliban, if possible, toward negotiations. Maybe the Taliban will never agree, but a continued U.S. effort is preferable to Afghanistan falling apart.