The last three consecutive American presidents all campaigned on promises of humility in the pursuit of American national interests, retrenchment from sprawling U.S. commitments abroad, and an end to the practice of “nation-building.” And then, in office, all three were compelled to retreat from their imprudent campaign trail commitments.

It took ten months for Barack Obama to agree to a surge in Afghanistan. It took eight months for George W. Bush to vow action against those who struck us on 9/11. Donald Trump, who made the most passionate case for a pull back, changed his tune earlier than either of his predecessors.

He seemed uncomfortably aware of the lofty promises he had made as a candidate in his Monday night address to an audience of servicemen and women at Fort Myer military base in Arlington, Virginia. “[A]ll my life I’ve heard that decisions are much different when you sit behind the desk in the Oval Office,” Trump conceded. That’s no cliché. In the course of this bout of public introspection, President Donald Trump positively savaged Candidate Donald Trump.

Full withdrawal from Afghanistan, which Trump said he initially favored, would instead be a disaster, he said. He admitted that America must honor the sacrifice of the men and women who lost their lives fighting to preserve Afghan sovereignty—including the son of his chief of staff, General John Kelly. His initial impulse, the president confessed, would create a vacuum that terrorist actors would undoubtedly fill. Finally, he conceded that isolationism is not an option. The world is a complex tapestry of interwoven interests and overlapping dangers. There is no way to neutralize the threats in Afghanistan without the support of regional partners and the aid of America’s allies around the globe.

In sum, Trump’s campaign trail persona was a grossly irresponsible affectation. If only someone had warned us.

In policy terms, Trump’s about-face means American troops will be in Afghanistan in augmented numbers. That isn’t news. As far back as June, the president revealed that he had handed operational authority over to the Pentagon, which subsequently announced an additional 4,000 troops would be deployed to the Afghan theater. We can assume more soldiers will be traveling to Central Asia soon enough.

What was news was the extent to which the president abandoned the pretense of Fortress America, even amid rhetoric designed to reassure his credulous supporters that he was still the same old Trump.

“We are not nation-building again. We are killing terrorists,” Trump insisted. “We will no longer use American military might to construct democracies in faraway lands or try to rebuild other countries in our own image. Those days are now over.”

We’ve heard it all before.

“I just don’t think it’s the role of the United States to walk into a country and say, ‘we do it this way, and so should you,’” George W. Bush averred in 2000. “Over the last decade, we have spent a trillion dollars on war, at a time of rising debt and hard economic times,” Barack Obama insisted just months after ordering the ill-fated withdrawal of U.S. troops from Iraq. “America, it is time to focus on nation building here at home.” This sounds lovely, and voters eat it up. But it’s unfeasible.

Trump pledged to secure a “win” in Afghanistan, but the most he can hope for is not losing. That means, first and foremost, leaving behind a functioning central government that controls both the capital and its provinces. It would be nice if that government was endowed with a strong civic culture and politicians not so corrupt that they alienate the public and make a fashionable alternative out of Islamist radicals. Whether we like it or not, tomorrow’s Afghanistan cannot be today’s Afghanistan. Not if Trump is to have peace with honor.

Trump spoke the truth about Pakistan’s clandestine support for rogue actors and organizations, and he should be praised for it. That behavior will ultimately confound America’s mission in Afghanistan if it persists. Unspoken by the president, however, was the problem of Iran’s and Russia’s ongoing efforts to assist insurgent groups. For its part, Moscow is open about its support for the Taliban. The Kremlin insists it is only trying to prevent the Taliban from being subsumed into an even more terrible organization like ISIS, but America’s generals believe Moscow’s efforts amount to little more than material support for an insurrection.

If Trump is serious about securing a noble peace in Afghanistan, that strategy will force him to engage in both nation- and coalition-building. Killing bad guys is all well and good, but the conflict in Afghanistan is being exacerbated by foreign governments, not insurgents hiding in caves.

This is not the first time that Donald Trump has unceremoniously repudiated his shallow, semi-isolationist pronouncements on the stump. “I don’t like Assad at all, but Assad is killing ISIS,” Trump said in October 2016. This necessary evil looked a lot less necessary from behind the Resolute Desk only months later, particularly after Damascus was implicated in a chemical attack on civilians this past April. The cruise missile strikes Trump ordered on Syrian regime targets may have been limited in scope, but they communicated Trump’s willingness to intervene on behalf of civilians. Samantha Power would have been proud.

Obama, Bush, and Trump surely entered office truly believing that a more humble application of American hard power around the world was in the best interests of the United States. They abandoned those beliefs not because these politicians were disingenuous or irresolute, nor because a cabal of military-industrialists corrupted these respective presidents. Retrenchment fails and is ultimately abandoned because it is a fantasy—one whose pursuit only results in chaos, instability, death on a scale that cannot compare to the alternatives.

American power projection remains a hobgoblin in the minds of many. Even today, Trump is drawing fire from the ranks of idealists who would, if confronted with the stark choices facing the president, do precisely as he did last night. Given the right conditions, we all become interventionists. Some of us are just more honest about that than others.