Our strategic, operational and technical defects were everywhere visible: inaccurate weaponry, zero capability at night, Army mismanagement, valueless intelligence, the lack of a sane, integrated air campaign—all these factors present and obvious at first hand. But in the middle of the in-country war and at the height of our military presence, there was a harder question, one that has echoed over the years: Why are we here?

You could make a case for intervention, and successive American administrations tried. We might prevent a Communist takeover of the South, just as Truman had kept North Korea from swallowing its southern neighbor. It was clear that if we could do this, success would have wider, potentially very important consequences. But we were on the wrong side of history, fighting a national independence movement intent on dissolving the residue of French and Japanese imperialism. It would be a stretch, but we could imagine a South Vietnamese government that was competent and honest. Even so, the mere fact of our support would undermine its legitimacy with its own people. There was really no way we could rescue the Saigon regime.

Moreover, it was obvious from the beginning that the outcome was far more important to the other side than it was to us, conditions strategically lopsided in their favor. Throughout the conflict, our design was to fight a limited war with a limited aim—the preservation of the South—against an enemy who fought an all-out war with the single-minded goal of reuniting the country, no matter how long it took or how much it cost. In the end, the North did lose more than one million dead and 300,000 missing—staggering numbers, something like 5 percent of the population it controlled. But the North Vietnamese believed, correctly as it turned out, that they could endure punishment longer and more stoically than we could dish it out.

In Apocalypse Now, Lieutenant Colonel Kilgore is the Pattonesque battalion commander whose nutty, marvelous “I love the smell of napalm in the morning” speech ends with the line: “Someday this war is gonna end.” Kilgore makes the assertion wistfully, without conviction, but he’s dead right. A country like ours will tolerate foolishness for a while, but not forever.