The US spent years fighting north Vietnamese forces only to sign a peace treaty, leave south Vietnam and then 2 years later have North Vietnam take over South Vietnam and unify the country.
You don't consider completely failing your objectives failure?
In both cases, Washington chose to stop sustaining a local government that could not survive on its own.
Saigon fell on April 30, 1975, which was a little over two years after the last US combat troops left Vietnam on March 29, 1973. US did not lose Afghanistan on the battlefield. US military overthrew the Taliban government, dismantled al-Qaeda’s sanctuary, killed Osama bin Laden, and prevented another major foreign-directed terrorist attack from Afghan soil for nearly twenty years. American forces were not defeated or driven out; they left because elected political leaders decided the mission was no longer worth continuing.
In both cases, the threats were eliminated. Hanoi is now friendly to the US. Iraq is friendly to the US. Syria is friendly to the US.
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.
US achieved major objectives, failed at building self-sustaining governments, and eventually withdrew.
It was a civil war that the US got involved in, and they supported the side that lost.
Who governs those countries matters, but America cannot spend unlimited blood and treasure ensuring that every country is governed by people we approve of.
The threats were eliminated. Mission accomplished.
Ask Pakistan if the threat of Afghanistan-based terrorism has been eliminated.