For the sake of a concrete POD, let's say around March 1965. Operation Rolling Thunder still commences, but LBJ decides against putting boots on the ground, instead sticking to the current policy of military "advisors" and slowly winding down the amount of US troops in the region over the next three years. What impact does this have on pop culture, the absence of the American disaffectedness that followed Vietnam, as well as the potential butterflying of President Nixon and the like? Your thoughts?
Note: If Tonkin is manufactured, we're committed.
If we're not committed to saving South Vietnam, then it falls pretty quickly. That probably seals Laos and Cambodia's fate, too, and perhaps steps up insurgency in Thailand. This Communist swamping of Southeast Asia may kill Johnson's reelection as badly as committing to Vietnam did.
But let's say LBJ focuses on The Great Society and maybe more dick-swinging in the Western Hemisphere. The economy is humming along, though not supercharged by the war. There's still plenty for the youth to rebel against--at 7 million students (compared to less than 2 million a generation before), they are a formidable faction.
Civil Rights remains the polarizing cry, even if LBJ can make the plight of the inner city a little more tolerable. The Generation Gap still exists because of the Baby Boom. British culture is virtually identical, as the UK stayed out of the war, and the POD is post-British Invasion.
Psychedelica is unaffected. However, if LBJ gets reelected, it may be less demonized. That was more of a Nixon bugaboo.
Maybe the money and energy we spent on Vietnam gets more applied to the Space Program--we beat the Russkies in more intangible ways. And/OR without Vietnam, maybe detente is arrived at earlier. Mao still does his thing, but the Soviets become chic. If Southeast Asia is mostly Soviet rather than Chinese clients, and Mao is the Great Satan of the '60s, maybe that's okay.
So, without Nixon, without the American defeat in Vietnam, come the early 70s, the White House myth remains intact, the Soviets are our partners in progress, and Trololo is a Top 40 hit played on American Bandstand. And a joint Moonbase is announced in '73.