Annapolis, Md.

THE costs of the second Iraq war, which began 10 years ago this week, are staggering: nearly 4,500 Americans killed and more than 30,000 wounded, many grievously; tens of thousands of innocent Iraqis wounded or killed; more than $2 trillion in direct government expenditures; and the significant weakening of the major regional counterweight to Iran and consequent strengthening of that country’s position and ambitions. Great powers rarely make national decisions that explode so quickly and completely in their face.

It may seem folly to seek a silver lining among these thunderclouds. But there are three flickers of light that offer some hope that the enormous price was not paid entirely in vain. These coins offer a meager return on our enormous investment, but not collecting them would be an insult to the memory of all that we have lost.

The first lesson is for America’s politicians, from both parties, who pushed our country into a war that we did not need to fight for dubious reasons that were eventually proved false.

Iraq was not, as we were repeatedly told, developing weapons of mass destruction; even if it had been, there was no reason deterrence, which prevented war with a nuclear-armed Soviet Union, could not have worked against a nuclear Iraq. There was no link between Al Qaeda and Saddam Hussein, and no Qaeda presence in Iraq until the American invasion, which caused social order to collapse and provided the terrorist group with a powerful recruiting message and a dangerous new base from which to attack.