Bac Ho took back the country he liberated from the french, renamed the capital city, instituted a communist regime that held its own against china.
War is a continuation of politics, and here, the US lost politically (in Laos first) even if they didn't loose strategically. But let's be honest, multiple times they got their asses kicked on the field too (Unless you think logistics don't matter for an army).
I agree the political objective ultimately failed. My point is that political failure is not the same thing as military defeat. The US withdrew; South Vietnam was defeated two years later.
I'm pretty sure we have different definition of what a win is, but i would like to understand your point of view, genuinely.