"War room" and "Wardroom"

This is a photograph of one of Winston Churchill's famous underground war rooms beneath the streets of Westminster from which the British war effort during World War II was directed. Why such a space should be called a war room should be uncontroversial.

Current usage extends this usage metaphorically to any space used for strategic planning, say, for a political or business campaign.

A wardroom is a space aboard a military ship where commissioned officers, but not the captain, dine or recreate: on land, the officer's mess. The word dates from the late eighteenth century and is derived from a no longer current use of ward to designate a company of soldiers or a garrison.

From roughly the same period as Churchill's war rooms, this is the wardroom of the USS Slater:

A space that is top secret, underground, and used for strategic operations during a war is highly unlikely ever to be confused with another on a naval ship where officers eat and hang out. Beyond a similar military context, the two words are utterly unrelated.

Both terms are valid, but have different meanings.

The meaning of war room is obvious from its parts, and clear uses in this sense date back to the early 20th century, for example The World's Work, Volume 3, Doubleday 1902 describes "The War Room at the White House". A later source describes what might be an earlier use: Readings in American Government and Politics, Charles Austin Beard Macmillan, 1909 discusses Lincoln's "War Room" (quotes and capitals in the original, so the author presumably felt the need to draw attention to the term.

It's not inconceivable that a war room (command centre) could have a neighbouring wardroom (naval version of an officers' mess) where the officers staffing the place eat and rest, at least if the navy were involved in running the facilities (officers' mess would of course be more common, and would be the term chosen by the army or air force).

The slight difference between an officers' mess and a wardroom is that on most warships the complement of officers wouldn't be large; the battlecruiser Hood had 81 officers, and of course a rigid watch structure. The RFC Armaments School (just one of several units at what later became RAF Uxbridge) had 114 officers in 1917, and while we might assume that some would always be on duty, unlike in the naval case for something like a (day) fighter base in the Battle of Britain, many of the officers would have been dining at the same time. Space is tight on a ship, hence a room; on land at an established the officers' mess was often a building.

Gentlemen, you can't fight in here! This is the war room!

https://www.youtube.com/watch?v=zSufJgCXwnw

Probably any use of "war room" in pop culture refers to this scene, this line.

And no, "wardroom" does not come into play.