How do you use United States as an adjective??

It's common to say: "France had US support" or "United States forces attacked." Is this grammatically correct? You wouldn't say "France has Canada support" or "Brazil forces attacked." It would be Canadian or Canada's, or Brazilian or Brazil's. So is it grammatically correct to use US or United States as an adjective, or is it just something that has fallen into general usage?

1 Answer
May 14, 2016
If the Army and the Navy
Ever look on Heaven's scenes,
They will find the streets are guarded
By United States Marines.


It's scandalous how the United States doesn't have an actual name, just a general description of how it's organized and where it's located. As inconsequential as this problem is, there are no adjectives like "United Statesian" (although there is a seldom-used Spanish term, Estadounidense). "American" technically refers to everything from Barrow, Alaska to Tierra del Fuego, but it's the generallly understood adjective for the land of Mom and Apple Pie. Somehow, people from the rest of the world know who we are. And sometimes, "United States" is description enough.