After 18 years of waging war in Afghanistan, the Trump administration is attempting to pull back. But critics have responded with outrage. What's the point of trying to reach a deal with the execrable Taliban? How can we contemplate abandoning the Afghan government when the country could be plunged into civil war or worse?

The implication of these objections is clear: Eighteen years has been insufficient. The U.S. should be willing to guarantee Afghan security and stability — including playing Whack-a-Mole with Taliban insurgents — with no end in sight. Anything less than such an open-ended commitment is tantamount to a surrender — and surrendering to America's enemies should be considered unacceptable, no matter the cost in blood and treasure.

There's just one problem with this line of reasoning: It's based entirely on a single false premise, one that has helped to justify every American military intervention since the collapse of the Soviet Union.

To understand it, let's start with Afghanistan. If we define American interests narrowly, to involve defending the American homeland from attack and the country's most vital strategic relationships with its allies and trading partners from interference by rivals and adversaries, the case for staying in Afghanistan is incredibly weak. The country is poor, feeble, on the other side of the planet, and no longer serving as a base of operations for terrorists with the capacity to launch international attacks. Even with significantly fewer troops in the country, the U.S. military will retain the capacity to strike quickly and decisively against any terrorist groups with international ambitions that seek to re-establish themselves.

But this isn't how critics of withdrawal think about our presence in Afghanistan. Instead, they make their case by referring to what they believe will happen once American troops leave the country. The Taliban are continuing attacks on civilians, Afghan forces, and American soldiers even as peace talks are underway. It's quite likely those attacks will accelerate once we withdraw, leading to the eventual overthrow of the Afghan government, civil unrest, and the return of the Taliban to power. The Afghan people would be abandoned, left to languish under the same theocratic tyranny that oppressed them before the American invasion of 2001. And that is morally unacceptable.

There is the premise: That it is in American interests to take responsibility for the security and protection of the people of Afghanistan. And that premise follows from a more fundamental and far-reaching one: That the internal politics of other nations is our business — because our interests are wrapped up with the fate of human rights around the world. When it comes to the specific case of Afghanistan, this premise implies that we should be willing to maintain a strong presence in the country indefinitely, for as long as necessary to prevent its fragile democratically elected government from collapsing in the face of domestic illiberal and anti-democratic forces.

But is this true? Are our interests really implicated in events that take place within a country 6,000 miles from American shores, even when very little that happens there is likely to directly affect life within the United States? What sense does it make even to think in terms of "interests" when they're defined by members of the bipartisan foreign policy establishment so expansively that events internal to a country of marginal geostrategic importance on the other side of the planet appear to adversely impact them?

In thinking through the answers to such questions, it's helpful to remind ourselves of how Americans, and eventually governments across the Western world, came to think in such terms in the first place.

Reeling from the successful but enormously costly effort to defeat the imperialistic totalitarianism of the Axis Powers, postwar policymakers opted for a strategy of confrontation and containment against the expansionist Soviet Union. For the next four decades, the U.S. sought to check communism around the globe. The effort took several forms. In Europe, it amounted to the placement of American troops and missiles on the continent as a tripwire to assure there would be no Soviet invasion of the West. In the recently decolonized countries of the developing world, it sometimes took the form of arming and advising Western-oriented factions fighting Soviet-backed forces in civil conflicts. But elsewhere — in Korea and Vietnam — it led to outright warfare, as countless thousands of American troops fought, and tens of thousands died, alongside local forces struggling against opponents heavily armed by our Cold War adversaries.

Nearly all of these military interventions were undertaken because policymakers were convinced that vital American interests, narrowly defined, were at stake in the conflict with Soviet communism. Yet that's not usually how we defended those policies, either at home or abroad. Instead, we deployed generous helpings of moral propaganda. America stood on the front lines of freedom, defending the friends of liberty against their foes. We were a force for good standing toe to toe with an evil empire. We were a city upon a hill, a beacon of democracy lighting the way for all mankind. Despite our own struggles with racism and oppression at home, we highlighted the suffering of communist dissidents and sought in a million ways to demonstrate to the world that the American side in the ideological conflict was superior because it led to better, more prosperous, and more peaceful lives for those who lived in the liberal democracies of the West.

In other words, we defended a policy rooted in realpolitik using a rhetoric of moralism.

One way to understand the trajectory of American foreign policy after 1989 is to see that after the Cold War was won policymakers began to believe in the truth of that conflict's propaganda. From the war to dislodge Iraq from Kuwait through the agonized response of the West to the genocides in Rwanda and the former Yugoslavia, the American-led countries of the West showed during the 1990s that they were losing the capacity to think strategically apart from moral concerns regarding the treatment of citizens within sovereign nations. It was in this period that the idea of fighting wars out of a "responsibility to protect" victims of injustice within countries first took strong hold in the minds of policymakers.

But it was only after the spectacular terrorist attacks of September 11, 2001, that this humanitarian impulse fully united with thinking about America's national interests. Now foreign policy analysts across the center-right and center-left thought and spoke in terms of vast tautologies that equated what was good for America with what was good for the West, good for Israel and the rest of the Middle East, and good for humanity everywhere. To disagree with America's actions in the world was to make oneself an enemy of civilization itself. You were either with us or with the nihilistic terrorists.

This mode of thinking reached an apex of sorts in George W. Bush's second inaugural address, which defended his own militaristic foreign policy as motived by nothing less than the goal of "ending tyranny in our world" and explicitly asserted that "America's vital interests and our deepest beliefs are now one."

It was such thinking that led us to stay in Afghanistan long after we had toppled the Taliban and wiped out al Qaeda's training camps. It helped convince Bush to invade Iraq, overthrow Saddam Hussein, and occupy the country for the rest of the decade. And led Hillary Clinton and many other prominent Democrats to support the invasion as well. And persuaded even a dissenter from the Iraq debacle like Barack Obama to support a miniature version of the same set of policies in Libya years later. And led many others to push him to intervene more aggressively in the morass of the Syrian civil war.

It's also what leads so many American policymakers and pundits, even now, to claim that the longest war in American history ought to go on even longer.

None of this means that decent people everywhere should hope for anything other than good outcomes and the alleviation of human suffering wherever it is found. We should do what we can, short of war, to smooth the path to reform in places embroiled in bloody civil wars and plagued by despotism. But that doesn't mean the bad things that happen around the world are our fault or responsibility. We should go to war, reluctantly, when necessity requires it, in order to defend ourselves. We should not go to war, or stay at war, to avenge someone else's injustice, or to provide security and protection to citizens of other countries. Our country has a duty to provide security and protection to us and to no one else in the world.

Until we stop imagining our interests are implicated in the treatment of people within other sovereign nations, the U.S. will remain embroiled in foreign wars across the globe, and remain forever tempted to start new ones.