We clearly won all the major battles. The war for the USA ended in January 27, 1973 with the Paris Peace Accords. Henry Kissinger even won a Nobel Peace Prize for negotiating the truce. We ended it with a draw. The South may have lost when the North Vietnamese came back almost two years later and took over, but we were no longer a combatant then.
two years later?... they were evacuating people by helicopter onto ships, running out of room and throwing choppers off the ships to fit more ppl at the last second...
the north completely took over and the country is entirely communist to this day...
for me, this constitutes a loss