AP Photo

The greater the sacrifice our forces make in Afghanistan, the worse the security situation becomes in that benighted country. At least, that seems the only logical conclusion to be drawn as millions of Afghans prepare to vote later this week in the second presidential election since the overthrow of the Taliban eight years ago.

The Taliban, it is true, are nothing like the fighting force they were when British forces were first deployed. The earliest British troops to arrive in the southern Afghan province of Helmand, the Taliban's traditional stronghold, faced some of the most intense hand-to-hand combat experienced since the Second World War. But though the Taliban have since been roundly defeated on the battlefield, they have adapted their tactics...