Which best describes the conclusion of u. s involvement in vietnam the vietnam war drags on and anti-war protests increase; president nixon begins pulling out american troops; south vietnam falls to the communist north president nixon escalates american ground troops in vietnam; with the of the south vietnamese troops, u. s defeats the communist north north vietnam quickly defeats the u. s, forcing american troops out of vietnam the u. s stays in vietnam until the south vietnamese can push back the viet cong into north vietnam. north and south vietnam stay divided after a cease-fire is signed