The White House effort to defend Defense Secretary Pete Hegseth on Wednesday leaned heavily into a semantic argument. What he posted on the now-infamous Signal chat with his national security colleagues was not a “war plan,” they insist.

Technically, they may be right. What The Atlantic published, from the chain in which its top editor, Jeffrey Goldberg, was inadvertently included, is more like a timeline of a pending attack. But it is so detailed — with the time that F/A-18F Super Hornet jets were supposed to launch and the time that MQ-9 Reaper drones would fly in from land bases in the Middle East — that the answer may prove a distinction without a difference.

A full “war plan” would undoubtedly be more specific, with the routings of weaponry and coordinates for targets. But that is not likely to help the defense secretary as he tries to explain away why he put these details on an unclassified commercial app that, while encrypted, was far from the heavily protected, classified internal systems used by the Pentagon.

And it was the time stamps he included in his messages, hours before the attack began, that were critical: Had this information leaked out, the Houthi fighters and missile experts the United States was targeting in Yemen would have had time to escape. Mr. Hegseth’s own references in the Signal chain to “OPSEC” — or operational security — indicated he fully understood the need to keep this timing secret.

And the level of detail was striking: “1215et: F-18s LAUNCH (1st strike package),” Mr. Hegseth wrote in the chat. “1345: ‘Trigger Based’ F-18 1st Strike Window Starts (Target Terrorist is @ his Known Location so SHOULD BE ON TIME) — also, Strike Drones Launch (MQ-9s).”

Clearly this is the most sensitive of battlefield plans. National security veterans say it was almost certainly classified data at the time that Mr. Hegseth sent them to the group chat. Yet the question of classification has been at the heart of the Trump administration’s explanations for why the Signal chat was a minor transgression.

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