Comment by dragonwriter

> And what if congress renames it tomorrow?

Then tomorrow it will be the Department of War. Just like When Congress voted to split the old Department of War into the Department of the Army and the Department of the Air Force, and to take both of those and the previously-separate Department of the Navy under a new National Military Establishment led by the newly-created Secretary of Defense (and when it later to voted to rename the NME as “Department of Defense”), things changed in the past.

> They have the votes.

Perhaps, but the law doesn't change because the votes are in a whip count on a hypothetical change, it changes because they are actually cast on a bill making a concrete change.