President Trump drew an odd historical parallel this week as he defended his decision to pull American support from allied Kurdish fighters in northern Syria, leaving them vulnerable to a Turkish offensive that began on Wednesday.

“They’re fighting for their land,” Mr. Trump said of the Kurds on Wednesday. “And as somebody wrote in a very, very powerful article today, they didn’t help us in the Second World War. They didn’t help us with Normandy, as an example.”

His words came as Turkey began an air and ground offensive against Kurdish fighters in northern Syria. So far, more than a dozen Kurdish fighters have been reported killed.

Where did that comment come from?

After the White House announced on Sunday that American troops would not defend Kurdish fighters in northern Syria from a Turkish military operation, Mr. Trump faced strident criticism — including from his Republican allies in Congress and United States military leaders. The Syrian Democratic Forces, a Kurdish-led militia in northeastern Syria, have been a crucial ally to the United States in the fight against the Islamic State, or ISIS.

Mr. Trump was discussing the issue in front of reporters on Wednesday when he invoked World War II history. The White House did not immediately respond to questions about why Normandy came up, or which article the president was referring to.