The Trump administration unveiled plans recently to send as many as 120,000 troops to Iran if American forces are attacked or if work on a nuclear weapons program is resumed. This stunning revelation, in the absence of any real provocation from Tehran, has justifiably caused great alarm for anyone who doesn't want to see the United States stumble into another ruinous war in the Middle East. It also should worry us about the overall trajectory of American foreign policy, as the U.S. looks increasingly like it is in dangerous decline — drunk on vanishing power, fearful of a reshuffling of hierarchies, and driven by emotional decision-making and irrational fears.

The United States today seems incapable of correctly appraising how its power to coerce other actors in the international system is diminishing. The wars in Afghanistan and Iraq waged this century not only failed to achieve even the most charitable interpretations of their objectives, but also further destabilized the region, empowered hostile actors like Iran, and should have confirmed for any sane observer that the United States lacks the ability to transform distant societies with military force.

Yet President Trump's administration continues to conduct foreign policy as if the United States is still the undisputed hegemon of a unipolar world, as it was in the decade following the collapse of the Soviet Union. Indeed, the administration's general attitude seems lifted directly from "The Unipolar Moment," a prominent Foreign Affairs essay written by the late Charles Krauthammer back in 1990. "The center of world power is the unchallenged superpower, the United States, attended by its Western allies," he wrote. He warned ominously of "the emergence of a new strategic environment, marked by the rise of small aggressive states armed with weapons of mass destruction and possessing the means to deliver them," and urged America to aggressively confront them in order to maintain its dominion over the world.

Both Democratic and Republican presidents over the past 30 years have crammed their thinking into Krauthammer's framework, flipping out over the slightest provocation from what became known as "rogue states," Iran prominent among them, and drawing the United States into a series of unnecessary and disastrous conflicts. But the immolation of America's designs in Iraq and Afghanistan led to a revision of American hegemony by the Obama administration — admittedly incomplete, and haphazard, but nevertheless meaningful efforts to extract the United States from the Middle East and from our seemingly incurable monomania to spend precious resources hounding and punishing poor, isolated countries with limited capacity to harm us.

Despite Trump's rhetoric during the 2016 campaign about the stupidity of Middle East entanglements, as president he has consciously or unconsciously returned to the pre-Obama framework of triumphalist, unilateral arrogance, without stopping even for a moment to consider the changed material circumstances facing the United States. The administration's failed efforts to railroad our NATO allies, the comical inability to bring dirt poor and isolated North Korea to heel, the humiliating impasse over the details of trade with China, and now this farcical effort to impose terms on the Iranians are all the follies of an over-the-hill global power that either does not recognize the emerging limits of its influence, or is gripped with panic over the impending erosion of American power.

Declining powers aren't just inept. They are also dangerous. A country whose power is deteriorating, particularly one that has fallen into the hands of an unstable ignoramus who is both terrifyingly aggressive with rhetoric and who has surrounded himself with unreconstructed militarists, could act aggressively with both rising challengers as well as less powerful countries like Iran.

What is most concerning about recent American foreign policy behavior is the extent to which it may be driven by the need to settle scores before our relative power declines any further. As political scientist Jack Levy explained in a 1988 World Politics article, "The temptation is to fight a war under relatively favorable circumstances now … to avoid both the worsening of the status quo over time and the risk of war under less favorable circumstances later."

America's bizarre obsession with Iran fits Levy's framework perfectly. Terrified that the Iran Deal might lead to an increase in Iranian power, the Trump administration set it on fire, and has since taken a series of aggressive steps designed to ratchet up tensions.

Apart from the egregious waste of time and resources on a weak and distant country that poses no meaningful threat to the United States, the Trump administration's Iran policy is fundamentally unworkable. The problem is actually much simpler than anyone would like to acknowledge. The United States today lacks the power to compel Iran to sign an agreement more favorable than the one the Trump administration tore up last year, and more importantly it lacks the expertise, resources, and political will to fight a protracted war. American threats are empty, not just because the president keeps saying in public that he doesn't want war, but because his goals are unachievable.

The truth is that America is deliberately running a trillion-dollar peacetime deficit in the middle of a decade-long economic expansion, and recently implemented a radical tax reduction plan. Fresh off spending $5.6 trillion despoiling Iraq and spinning our wheels in the endless Afghanistan quagmire, the United States can ill afford to prosecute a border skirmish, let alone a full-blown war with an enormous country of 82 million people. Not only that, but the odds of getting appropriations for an Iran war through the House of Representatives are steep.

On top of all that, while the public may have been split on the wisdom of invading Iraq in 2003, there is no such division about Iran today. A poll from last summer found just 23 percent of Americans support a war against Iran, or whatever madness the deployment of over 100,000 troops to the region portends. Shorn of any kind of domestic mandate for a confrontation, the Trump administration also lacks utterly the buy-in of allies outside of the Gulf Arab tyrannies whose disputes with Tehran really should be none of our concern whatsoever.

Hawks like Sen. Tom Cotton (R-Ark.) might float the idea of brief airstrikes to bring Iran into line, but this is a fantasy, a staple of conservative war-porn that has never been pursued because it would obviously be a disaster. Short of an invasion, the U.S. simply cannot feasibly prevent an Iranian nuclear breakout without a constant bombing and containment campaign that has no legal justification, no domestic or international support, and which would quickly wear out its welcome in the region. It is worrisome that the president might allow himself to get talked into war by people who are fundamentally in denial about this basic reality — advisers whose worldviews were shaped by America's brief cameo as an unassailable bully, and whose desire to restore an extinct hegemony might lead them into our most dangerous hour yet.