KABUL — A five-day visit to Afghanistan left me profoundly pessimistic about the accomplishments to date to stem the drain on international blood and treasure, yet convinced of the importance of not losing Afghanistan to the other side.

Kabul defined the pessimism: After more than seven years of massive security operations, travel in the capital city was permitted only in armored cars and if one wears a bulletproof vest.

Bamiyan defined the determination not to abandon the fight: Gaping hillside holes from the two giant Buddha statues, which stood as silent sentinels for more than 1,500 years before the Taliban destroyed them in an act of willful cultural vandalism.