The announcement of the end of the Afghan war by the twentieth anniversary of 9/11 is significant. Once coalition forces leave, the government in Kabul could be overthrown, and the Taliban could come back. Yet when we started this thing twenty years ago, removing the Taliban from power was the point. So the longest war in US history is ending in failure.

Beyond that — and this is where I get into speculation — his statement announcing that the United States is leaving by September contains hints of further reduction in the American military footprint. If that happens, it’s an indication that this administration is aware of the fact that the premises defining US national security policy since the end of the Cold War, not merely since 9/11, have been proven false.

Which premises? One was ideological. The Cold War had left one superpower, one surviving model — liberal democracy, the way we practice it — and that model would be adopted universally. The other was the perception of US military supremacy.

Historians will pay attention to the significance of two events: the end of the Cold War, and the first Iraq War — the first large-scale military campaign since Vietnam. When it was on the verge of being undertaken, there was lots of hand-wringing: “This will be another quagmire”; “there’ll be lots of casualties”; “Saddam has a battle-tested combat army.” Then Desert Storm unfolded, and it was a clean, quickly won victory with few casualties. Those two notions — ideological supremacy, military supremacy — provided an overarching through line of US policy up until the election of Donald Trump.

And they didn’t work. It turned out there are alternatives to liberal capitalism, one of which we see in China, and the other thing we found out is that we are not militarily supreme. We were getting involved in wars we couldn’t win.

I think Biden and his people understand that the basic premises of the post–Cold War era have failed. Their challenge is to figure out what to replace them with. What should America’s role be in the world once we realize we’re not the indispensable nation, when we recognize we’re not militarily supreme?

Besides this failure, what else do we see coming? One is a serious recognition of the danger of climate change. If we want to make a dent in climate change, we have to cooperate with the Chinese.

They’re jumping to conclusions, and we need to avoid that conclusion. We need to compare the Soviet Union in the 1950s, ’60s, and ’70s with China, as adversaries. The ideological element of the Cold War was based on the perception in the West that the USSR was trying to export a very specific ideology that was hostile. I don’t think there’s that same competition with China. I don’t see evidence that “Xi Thought” is exportable.

The capabilities are also different. We used to call it a bipolar order, where two superpowers on par with each other indulged in competition. That was never true. The Soviets developed a real capability to make pretty good weapons, especially nukes and long-range missiles. They were formidable. But the United States was ahead of them on every other level.

Compare that to China. Whatever they make, we want, and they make high-quality consumer goods. They have a formidable military, but not as big as the USSR, which had an army in the middle of the Warsaw Pact that we worried we’d have to defend against. The Chinese nuclear arsenal isn’t huge; I wouldn’t dismiss it, but they’re just not a military power like the Soviets were.

Now, the Chinese have ambitions, and they clearly intend to be treated with the respect of a great power. The destiny of Taiwan, or Hong Kong, or the islands in the South China Sea are problematic for those nations, and they’re problematic for us, but it’s not as if China is trying to take over the damn world.

And then you’ve got to remind yourself that they keep lending us money so we can buy stuff. We’re in their debt. So the notion that the Cold War somehow provides a model or template for the current US-China relationship is deeply flawed.

There’s no question that, in the national security state, there’s a search for the new enemy that will maintain the ability of the national security state to lay claim to resources on a mammoth scale.

The rise of China suggests post–Cold War kind of thinking is simply obsolete. It suggests the era of American primacy is over, that there’s going to be at least two or three superpowers, and that the United States has to accommodate itself to that. It’s difficult for people, especially those who are in the realm of politics — think tanks, diplomacy, working within the military establishment — to acknowledge the fact that the era of American primacy is over, because once you admit that, it also opens the doors to a wide array of questions.

Do we need to have eight hundred foreign bases? Or a national security state that approximates $1 trillion a year? And do we have to design US forces as we do for power projection, meaning that they’ll go out there somewhere and fight? And, given how climate change is affecting us, could we have a national security apparatus that defends us where we live? That thought has huge implications for what kind of air force we have, and so on.

I think so. Right now, there’s the inclination to see force as the primary instrument to advance US interests. I think it will become easier to recognize the benefits of diplomacy.

In the specific example of the Persian Gulf, since the Carter Doctrine, we’ve been engaged in a series of military campaigns to reorient the Gulf. It hasn’t worked, but it’s cost us a lot. If we acknowledge that that has failed, then it seems to me that encourages a greater recognition of alternatives. Maybe instead of taking sides in the competition between Saudi Arabia and Iran — right now we’re with the Saudis, and we’re sending them more money and weapons than you can shake a stick at — maybe we should nudge those countries to some sort of accommodation. It would be tough, but we thought it would be easy to remake Iraq, and that was tough.

It also provides an opportunity to try other approaches to solving problems. Lowering our profile internationally creates opportunities to redirect resources from the Pentagon toward home.

The honest answer is: I don’t know. Clearly there is some rethinking in some European capitals. [Emmanuel] Macron gave a speech in which he basically said that Europe needs to assert an independent identity, not be submerged into some larger thing in the United States. I have no idea if that idea has any traction. Although when Trump was in office, there was a tendency to see his presidency as a very sharp break, an abandonment of the post–Cold War arrangements, today those notions are already being set aside, and old arrangements are being restored.

As for the pandemic, it’s too soon to tell. What would be interesting is if one of the two parties constructed an argument that the pandemic marked the decisive turn in the conception of national security, and here are the things that should follow as first principles of US foreign policy. We would pay much more attention to proximate threats to American people where they live, rather than distant threats to people out there, in the Indo-Pacific or the Persian Gulf.

At the same time, the pandemic of 1918 was a horrible thing, but it appeared that once it passed, it was gone, and the politics of the 1920s going forward were not affected in any significant way by it. There were all kinds of other issues in the 1920s that Europeans got excited about that Americans were drawn into.

Or around race. Race has always been a problem in American history. But there does seem to have been a recognition of the need to have a real reckoning on the question of race, and issues around race have now risen to the top. If that sticks with us, it could have a very real impact on US national security policy.

If we think about the preferred American history of the twentieth century from 1919 to Iraq, it’s a race-based narrative, that freedom-loving white people confronted totalitarianism and defeated it. It’s a history written by white, mostly males, and one we tend to embrace, because it’s very reassuring.

If race becomes the defining issue, if racism or imperialism displace totalitarianism as the crime of the century, the twentieth century looks a lot different. It’s not an issue of freedom vs. un-freedom, because guess what? The representatives of freedom — us, the Brits, the Dutch — all of them engaged in imperialism justified by racism. And it becomes a lot more difficult to lay claims that mostly white Western nations represent virtue.

It’s too soon to tell. If race becomes the defining issue of the moment, it could be that the poverty of people of color in places like Africa or Southern Asia or Latin America could actually come to seem more important than dealing with China. And that could have a radical impact on foreign policy priorities.