We did not really require further confirmation that Donald J. Trump doesn't know much about foreign policy, but we got it this weekend, in the form of a lengthy interview by Maggie Haberman and David Sanger of the New York Times.

Despite not knowing much, Trump held forth for about 15,000 words' worth of foreign policy talk, and somewhere in there managed to reveal, intentionally or not, some of how he thinks about the world and America's role in it.

Here are a few things that, in my view, this interview showed us about Trump and foreign policy. None of it is revelatory — these are largely points he's made before, now just at length. But they are nonetheless illustrative, and left me with a picture of someone whose worldview is both simpler and stranger than the sort of realist isolationism that is typically ascribed to him.

1) Trump doesn't really understand the post-WWII international order

Trump's foreign policy often gets discussed as isolationist for its skepticism of allies and foreign entanglements, or as realist for its obsession with self-interest and with cold cost-benefit. In either case, the theory is meant to explain why Trump so disdains virtually every facet of America's international role, from its alliance networks to its foreign military bases and security guarantees.

But the more you hear from Trump, the clearer it becomes that something else is going on: He either does not believe in or simply does not understand the international order that has governed the world since the end of World War II.

This comes through in Trump's declaration that postwar alliance systems such as NATO are "obsolete."

"NATO is unfair, economically, to us, to the United States," Trump said. "Because it really helps them more so than the United States, and we pay a disproportionate share."

This suggests Trump does not understand that these alliances are part of a global order meant to codify the status quo, deter interstate conflict, and thus maintain global stability, thereby both preventing a return to the catastrophic wars of the early 20th century and cementing America's preeminent global position.

"We’re defending the world," he said, apparently meaning it as a complaint. "When in doubt, come to the United States. We’ll defend you. In some cases free of charge."

This is part of why foreign policy professionals tend to express such alarm when Trump suggests that he might reconsider, say, American involvement in NATO. It's not just about NATO. Whether he realizes it or not — and I suspect he doesn't — Trump is threatening to tear up the international system on which the US and much of the world relies.

This is "America first" at its most shortsighted, sacrificing an international system that is the basis of American power and American security.

Trump's foreign policy is a little like calling for the United States to abolish all government so we can save money on taxes. At some point, every high school civics student learns that taxes fund the government, which provides security and infrastructure, which allows us to have jobs and income in the first place, as well as live past the age of 30.

This is much like how the international order works: Countries pay into it such that there is a functioning and basically stable world. Trump doesn't seem to understand this, rather seeing the world as just a place where countries go to make deals.

This leads him to assume that Europe will always be peaceful and stable, and international trade will always be free and open. Therefore, in his mind, there is no reason to invest in things like NATO or open sea routes; those are just deals we make with other countries, and if we don't get favorable enough terms it's fine to abandon them.

That makes a lot of sense if you have no idea what the international order is or how it works, and it does not seem that Trump does.

2) Trump wants to sell American credibility for money

As you may have heard, Donald J. Trump loves a good deal. And there's one kind of deal that Trump in particular sees as ripe for the taking: leveraging American credibility to extract cash from allies.

We have all of these security guarantees and alliances, and they're very important for the American allies who rely on them. Trump, as he says repeatedly, thinks the United States could and should get "better deals" on these, by which he typically means those countries should pay cash directly to the United States.

Trump, for example, decried that the US is "protecting Saudi Arabia and not being properly reimbursed for every penny that we spend, when they’re sitting with trillions of dollars. ... And we were paying leases for bases?"

Trump's plan for how to get those allies to pay up is to threaten to withdraw from the alliance or security guarantee altogether.

And, indeed, that does make sense if you see these alliances and commitments as nothing more than fancy sorts of business deals, as things that matter solely for the amount of money they bring in. And it makes sense if your primary objective in foreign policy is to get more money.

It does seem likely that if Trump comes into office and threatens Europeans that he will withdraw from NATO unless they increase their share of NATO-wide defense spending, or threaten to withdraw American troops from South Korea unless that country pays cash to the US, then these threats will work in securing more money from allies. The era of Good Deals will be upon us.

But that era will also bring an arms race in Northeast Asia, potentially a nuclear arms race, as states there prepare for the threatened withdrawal of America's nuclear umbrella. It will risk the same in the Middle East, exacerbating already deadly security competition between Iran and the Arab states of the Gulf. And it will bring unpredictable but likely destabilizing change to Eastern European countries that rely on the US to provide a security guarantee against Russia, which they are too poor to do on their own.

It is not necessary for a President Trump to actually withdraw American security guarantees from these regions in order to prompt these reactions. Trump believes a credible threat to withdraw will get him better deals, and maybe it will. But if the threatened countries take those threats seriously, they will begin hedging for the possibility that this threat is carried through, which means assuming that American support is unreliable.

This is a doomed strategy even just on the narrow terms that interest Trump. By mortgaging against American credibility and security guarantees today, he weakens them in the long term, reducing our ability to maintain a world that favors American interests and in which everyone has to listen to us — thereby reducing our ability to get more Good Deals in the future. (And along the way it will invite a good deal more conflict and chaos in the world, which is costly for everyone, including the US.)

3) Trump wants America to become more like a rogue state

Trump's favorite word in his New York Times interview is "unpredictable."

"We need unpredictability," he says. "Would I go to war? Look, let me just tell you. There’s a question I wouldn’t want to answer. Because I don’t want to say I won’t or I will."

Unpredictability is central to the Trump foreign policy doctrine. So is an emphasis on zero-sum relations with all nations, a disdain for allies, a status quo position of belligerence and uncooperativeness, a strategy of using leverage and bullying to extract concessions from other countries, and an innate suspicion of the international order.

What Trump is describing, in his vision of American foreign policy, is what we might otherwise call a rogue state.

Trump's America is, like North Korea or at times Putin's Russia, a rent seeker leeching off the international order rather than upholding it.

That's especially bizarre given that the United States is powerful enough that it doesn't have to rent-seek, and it certainly doesn't have to undermine the global order, which after all we helped design to maximize American interests.

Consider Trump's plan to "take" Iraq's oil by force to recompense the United States for the 2003 Iraq War.

"I said take the oil. I’ve been saying that for years," he said. Now, though, he says the US should destroy Iraq's oil, so as to remove ISIS's ability to access those fields. "We should’ve taken it and we would’ve have it. Now we have to destroy the oil."

4) Trump sees himself as applying business savvy to foreign policy, but shows profound ignorance of even basic business concepts

Taken together, these points suggest that Trump sees the core concepts of international relations — deterrence, alliance structures — as nonsense, preferring short-term transactionalism. He sees the world as something like a big real estate development, and its nations as little more than competing contractors and developers.

And he sees himself as a savvy businessman who, by use of leverage and (painfully transparent) psychological games, can secure the best outcome at the least cost.

Yet for such a self-celebrated businessman, Trump seems to have remarkably little understanding of, or interest in, even basic concepts of business that might apply to foreign relations.

For example, if he understood that a cartel of firms can control the market to the benefit of its members, he might have greater enthusiasm for alliance structures such as NATO, which control security in Europe, thus ensuring that the US will not have to once again intervene in a costly European war.

Similarly, the idea that America should invest in international institutions to maintain rules and norms that favor America's preeminence — seemingly a familiar notion to an entrenched New York developer who wants the city to pass regulations that protect his investments and keep out competitors — seems completely alien to Trump.

Even the idea of a long-term investment that brings a reliable source of dividends — name any one of the alliances he would like to ditch as too expensive — seems lost on him.

5) Trump just does not understand how foreign policy works

It's easy to overcomplicate this. But the core issue is that Donald Trump gives every indication of having no idea what he is talking about.

As international relations scholar Dan Drezner writes in a column titled, "The trouble with writing about Donald Trump," this is actually not that complicated: "He’s basic and bad. There’s really nothing else of substance to say."

That's not just to take a swat at Trump; it helps explain the prior four points I am making here. Consider, for example, this exchange with David Sanger, where Trump begins by complaining that removing sanctions from Iran will allow the country to do more business abroad, and then complains that Iran is not doing more business abroad:

TRUMP: Certainly the deal is not long enough. Because at the end of the deal they’re going to have great nuclear capability. So certainly the deal isn’t long enough. I would never have given them back the $150 billion under any circumstances. I would’ve never allowed that to happen. They are, they are now rich, and did you notice they’re buying from everybody but the United States? They’re buying planes, they’re buying everything, they’re buying from everybody but the United States. I would never have made the deal. SANGER: Our law prevents us from selling to them, sir. TRUMP: Uh, excuse me? SANGER: Our law prevents us from selling any planes or, we still have sanctions in the U.S. that would prevent the U.S. from being able to sell that equipment. TRUMP: So, how stupid is that?

The issue is not just that Trump has very strong opinions on the Iran nuclear deal and sanctions relief despite seeming to have no idea what is actually in that deal.

Worse, it is that Trump seems to literally not understand the purpose of sanctions. If he does understand them, he is unable to carry that understanding through a complete thought before calling for policies that are not just mutually exclusive but that also lead to contradictory ends.

Trump wants to sanction and punish Iran, but he also wants to open up more trade with it, all within the same paragraph. This is the reasoning of a person who lacks something more fundamental than detailed policy knowledge — he lacks an understanding of how foreign policy itself, at a fundamental level, functions.

This perhaps helps explain why he wants to actively undermine a post-WWII international order that is America's most valuable and important asset, wants to rent-seek and resource-extract from a world already inclined to favor American interests, and wants to sell off long-term American power in exchange for a little more money from our allies. Because he just doesn't get it.

President Obama on the goal of his foreign policy