THE BURNED OVER DISTRICT

Actually the parting thoughts of retiring Ambassador Ryan Crocker are damn good advice for people not blinded their own agenda.

The American diplomat most associated with the invasions of Iraq and Afghanistan says that American policy makers need to learn the lessons of the recent past as they weigh military options for the future, including for Syria and Iran:

¶ Remember the law of unintended consequences.

¶ Recognize the limits of the United States’ actual capabilities.

¶ Understand that getting out of a conflict once you are in can often be dangerous and as destructive for the country as the original conflict.

“You better do some cold calculating, you know, about how do you really think you are going to influence things for the better,” said Ryan C. Crocker, 63, the departing ambassador to Afghanistan and one of the pre-eminent American diplomats of the past 40 years. Even as he retires fighting an exhausting illness, Mr. Crocker cannot help keeping his mind at work on the crisis spots that have defined his career — in Pakistan and Afghanistan, Iran and Syria, Iraq and Lebanon.

Mr. Crocker, a wiry, intense man who for years was a dedicated distance runner, is retiring at the end of July after a career that began as the last American troops were leaving Vietnam and is ending as the curtain closes on an era of American state-building that has mostly fallen short of the results policy makers had hoped for.

In Iraq, the dream of a peaceful and democratic ally in the Arab world is giving way to a renewal of violence and an authoritarian government that lists toward Iran. In Afghanistan, the future is uncertain and hangs on dozens of “ifs” — if the elections are fair enough, if the Afghan security forces can fight off insurgents, if the government can become self-sufficient.

In the years ahead, Mr. Crocker sees, if anything, an increasingly fraught foreign landscape in a world set afire by war and revolution, a chapter bound to frustrate the best intentions and most sophisticated strategies of the United States. Although he speaks Arabic and has spent a lifetime immersed in the Arab world and Afghanistan, Mr. Crocker is deeply skeptical that Americans on foreign soil can be anything other than strangers in a strange land.

“We’re a superpower, we don’t fight on our territory, but that means you are in somebody else’s stadium, playing by somebody else’s ground rules, and you have to understand the environment, the history, the politics of the country you wish to intervene in,” he said.

Understanding others is one of the great exceptions of these United States. We gave ourselves a waiver of that many, many years ago.