Gary Johnson made headlines today for all the wrong reasons:

Gary Johnson, the former New Mexico governor and Libertarian Party presidential nominee, revealed a surprising lack of foreign policy knowledge on Thursday that could rock his insurgent candidacy when he could not answer a basic question about the crisis in Aleppo, Syria.

“What is Aleppo?” Mr. Johnson said when asked on MSNBC how, as president, he would address the refugee crisis in the war-torn Syrian city.

Johnson’s error was an unforced one. In addition to making himself look ridiculous, he missed a perfect opportunity to challenge some of the assumptions behind the question he was asked. When Barnicle asked him what he would do about Aleppo as president, he could have questioned why an American president should be expected to “do something” about a city in a foreign civil war. He might have challenged the idea that it is the responsibility of the U.S. government to fix things on the other side of the world. He could even have pushed back on the framing of the conflict implicit in the question. But that would have required him to be much better prepared to address these issues than he was. As it was, he gave a rambling answer that touched on the muddled nature of current U.S. policy, but he didn’t explain why the current policy was wrong except to say that it is a “mess.” Johnson’s proposal for what to do in Syria–“join hands with the Russians” in a diplomatic effort–was not terrible, but it was little more than a talking point and wouldn’t persuade anyone that didn’t already agree with it.

As campaign flubs go, this is hardly the worst one we have seen this year. Trump has repeatedly demonstrated far greater ignorance of more important foreign policy issues. Clinton has labeled the Libyan debacle as “smart power at its best,” which ought to be thrown back in her face with every new report of the instability and violence that she helped to create in that country. Nonetheless, because Trump and Clinton are both so awful on foreign policy in different ways it is all the more important that third-party candidates demonstrate that they have better foreign policy judgment and understanding than the major party nominees. Johnson had a chance to do that today, and he blew it.

P.S. It’s worth noting that the Times article reporting Johnson’s flub misidentified Aleppo a couple times before settling on its latest version. The first version called it ISIS’s “de facto capital” and the second called it an ISIS stronghold. Johnson is hardly alone in not being all that familiar with the details or geography of the Syrian conflict.