Nuclear War, between the European states that have Nuclear Weapons and Russia and China (Republicans and Congressional Liberals successfully block U.S Intervention)
Russia ends up occupying a European wasteland (as they have more nukes than Europe) With the exception of Britain, which they don't bother to occupy.
Putin considers preemptively bombing the U.S, but decides against it.
Please, they got 77 Senators and most of the House to vote for a completely unjustified war. This would obviously pass Congress.
77 Senators voted for an unjustified war against a government no one anywhere doubted we could beat with minimal effort.
Not the same as with Russia.