Two? And we "lost" Vietnam politically, not militarily. We were bombing the hell out of Ho Chi Min city, the NVA's military pretty much consisted of nothing but their generals, and we'd effectively fought the war six times over and beaten them six times over with how many times Congress told us to stop for "peace talks" which they just used to regroup and resupply. The military was doing fine in every way, except in the public's eyes. Our kill-death ratios versus the Vietnamese were climbing to never before seen records in any previous war, and our pilots were getting better by the day. We had them outgunned, outmanned, outteched, we were killing them faster than they could kill us, taking strategic points like it was no bodies business, et cetera.
And then Congress happened.
We underestimated our enemies at first. Then we stopped and learned.
The military really doesn't lie as much as you'd think. Half truths, certainly. They'll beat the hell out of omitting information, but lying, not so much. This isn't Hollywood where the military is some giant faceless entity whose soldiers wear masks so you don't have to think of them as people, where conspiracies run rampant and soldiers don't give a crap about their countrymen.