Look guys, I found the Grammer Nazi.

This is wrong. That would describe a certain type of war, but specify that the war is movable.

I think the "Torpfostverschiebekrieg" mentioned in another comment would be the best solution.

But surely wouldn't that imply the existence of such thing as a 'goal post war'? Because the term is meant to mean '(moving goal post) (war)', and not '(moving) (goal post war)'

On the other hand in Finnish that's can be one word: maalitolpansiirtosota. No sense implied.

„Torpfostenbewegungskrieg“ would be correct. I‘d prefer „Torpfostverschiebekrieg“ though.

It's incorrect actually! We don't compound adjectives (Beweglicher)