this too shall pass

The absence of substantial U.S. casualties in this conflict also masks the scale of the U.S. defeat. To be sure, the war has been deadly: Thousands of Iranians, combatants and civilians, have died in the fighting. Americans, however, have endured far fewer deaths: To date, fewer than 20 U.S. soldiers have died—and many of those in a single strike.

By comparison, the scale of what the Vietnamese call the American War is breathtaking. Millions of people, mostly civilians, died in more than a decade of fighting waged over much of the skies and jungles of Southeast Asia; of those, just under 60,000 were Americans.

So bitter was the experience that, for a generation, when Americans mentioned the word “Vietnam,” they did not refer to the actual country or society that bears that name—about whom they remained largely ignorant even after years of struggle. In American usage, Vietnam was understood to be primarily a metaphor or a symbol for an American experience.

To many ordinary Americans, it meant personal grief. For some elites, Vietnam was a cautionary tale about the hubris of power; for others, it was an error that hindered proper strategic calculation in the present. There was, however, a national consensus that Vietnam was a stain on the national fabric: A 2014 Chicago Council on Global Affairs poll found 58 percent of Americans described it as a “dark moment” and only 12 percent as something to be proud of.

The most difficult point to grasp about that conflict today may be why the United States fought so hard given how little the conflict turned out to matter to Washington. For all that U.S. policymakers waging war tolerated what would now be almost unimaginable casualties, U.S. failure in the war ultimately mattered little to broader American strategic objectives. As early as 1964, internal U.S. government debates questioned the “domino theory”—the idea that one country becoming communist would lead to its neighbors following—that would become popularly identified with the U.S. war in Vietnam.

That the war was ultimately irrelevant to Americans is not to say it was unimportant. The destabilization of Southeast Asia mattered: The mass graves of Cambodia bear mute witness to the toll of a conflict whose consequences spread beyond Vietnam’s borders and after a peace had been officially signed. The result of the war mattered to Vietnam, as did the desperation of the refugees who fled in the years to come.

Yet those observations do not change the fact that, for the United States itself, the consequences of a costly defeat were, in the long run, relatively minor and inward-looking. The United States emerged from the wider Cold War triumphant. Vietnam itself is a power surprisingly friendly to the United States today.

Compare that situation with the aftermath of Trump’s war. The United States is inarguably in a weaker position than when it began this war of choice, with core U.S. strategic objectives harmed.

Contrast how its military performance has seemed during this conflict with the U.S.-led coalition’s war to reverse Iraqi President Saddam Hussein’s conquest of Kuwait. In the 1990-91 conflict, the seeming ease with which Iraq’s military was dismembered stunned the world.

By contrast, the technically superior performance of U.S. arms in the Iran conflict has been overshadowed by the shallowness of U.S. arsenals, calling into question U.S. preparedness for a conflict with any foe more powerful than the Islamic Republic. The lasting image of high-tech combat from this conflict will be the blood-spattered bags of Iranian schoolgirls killed as the result of an apparent database error. And although U.S. defensive systems have performed well against Iranian missiles and one-way attack drones, Iran was nevertheless able to penetrate those systems to great effect, calling into question how those systems would fare against a more focused enemy or over a longer conflict.

Strategically, the outcomes are far grimmer. The United States achieved regime change of a sort: Rather than turning Tehran into a pliable client, the war made Iran more hard-line, leaving the Islamic Revolutionary Guard Corps effectively in charge of the country. Israeli and U.S. arms, however brutally effective in the first days of the war, ultimately demonstrated the limitations of kinetic solutions, to Iran’s great benefit. Iran’s nuclear program has now endured two rounds of joint Israeli-U.S. airstrikes. It seems unlikely a third would fare much better.

The effects on U.S. leadership in the global system have been more profound. Regional allies, many of whom reportedly argued against the venture, bore the brunt of the costs of the fighting. Most tellingly, Iran learned that its capacity to throttle the Strait of Hormuz could deliver economic leverage on a worldwide scale.

Freedom of navigation has been a core U.S. strategic objective for more than two centuries; President Thomas Jefferson dispatched the Navy to halt tributary payments to Mediterranean powers in the early 1800s. The potential end of free passage of the Strait of Hormuz could portend a weaponization of trade routes with enduring and potentially grievous harm to world commerce.

The manner in which a war ends can tell as much as how it begins. After the American War, the United States could largely turn its back on Vietnam and its neighbors and concentrate on areas of greater strategic importance. Although some combination of a global shift to green energy and the hydrocarbon production of the United States might make a similar exit from the Gulf region attractive to at least some in Washington, it will be difficult to copy the post-Vietnam departure.

The world economy is, after all, more interwoven today than in the 1970s, and the Gulf plays a greater role in economic networks today than Indochina did decades ago. Global supply chains are wired to depend not only on Gulf hydrocarbons but on its helium, fertilizer, and aluminum. The linkages are not only economic. Continuing U.S. ties to Israel make a complete exit from the region unlikely and raise the prospect of further, perhaps more intense, fighting. The development of Iran’s missiles, and potentially its nuclear program, makes the prospects for the 2030s much more dire not only for the region but for Europe and South Asia as well.

The United States, under whatever management, will confront these consequences while being itself weakened at home and abroad. Its allies will have less confidence in its capabilities; its public will be less willing to bear the costs of even productive engagement; its rivals will be likelier to challenge Washington’s will. Those results will be far more lasting and severe than the U.S. failure in its war in Vietnam.