So, here's a thing you're not supposed to say if you're the U.S. Secretary of Defense: "no quarter." Senator Mark Kelly (D-Ariz.) wants to know if Pete Hegseth knows that.

Kelly has formally demanded that Hegseth explain his recent comments about U.S. military operations, specifically his statement that "we will keep pushing, keep advancing, no quarter, no mercy for our enemies." The problem, as Kelly points out, is that "no quarter" isn't just tough-guy talk. It has a very specific, and very illegal, meaning under the laws of war.

"It's well established that it means to take no prisoners — to kill them instead of accept their surrender," Kelly wrote in a post on X. In a formal letter to the Pentagon, he elaborated that the phrase "historically, and legally, refers to a declaration by a military commander that no enemy combatants can be taken prisoner- that is, that they are to be killed rather than permitted to surrender."

This isn't a minor breach of etiquette. Declaring "no quarter" is banned under international agreements like the Geneva Conventions and the Hague Conventions. Under the U.S. War Crimes Act of 1996, it could constitute a war crime. Kelly is asking Hegseth to clarify whether his statement reflected actual U.S. policy or rules of engagement, and to confirm that U.S. operations will comply with international law and that service members understand their duty to refuse unlawful orders.

It's a serious question posed in the middle of a serious conflict. The demand for clarification comes alongside other updates on the U.S. situation with Iran. A senior White House official said Sunday that the Pentagon expects the conflict to last several more weeks, with Americans facing higher energy prices as a result. Kevin Hassett said the military estimated the operation could take four to six weeks and was progressing faster than expected.

Meanwhile, there's scrutiny on how the Pentagon is spending money. Last week, Senate Minority Leader Chuck Schumer (D-N.Y.) criticized defense spending after reports showed Hegseth oversaw $93 billion in expenditures in one month, with allegations the funds were spent on luxury items rather than public needs.

Hegseth has also acknowledged that more American casualties are likely as operations continue, stating that losses would strengthen U.S. resolve. He added that the administration is monitoring reports that Russia has shared intelligence with Iran on U.S. military positions and said the U.S. is adjusting its planning accordingly.

So, to recap: a top senator is asking the defense secretary if he just threatened a war crime, all while a conflict drags on, spending is questioned, and the geopolitical chessboard gets more complicated. It's a lot for a Monday.