Donald Trump’s coziness with Vladimir Putin, casual talk of forcing Mexico to build a border wall, and muddled messaging on whether he'd start a trade war with China makes it easy to assume that the president-elect’s foreign policy is a jumbled mishmash of ideas lacking any coherent philosophy.

That couldn't be more wrong. In fact, a close look at Trump’s public comments leads to a very different conclusion: Trump has a distinct worldview that knits together many of his specific proposals. It can be summed up in a word: transactional.

In Trump’s conception, all of foreign policy is motivated by assessments of what's better, in a narrow financial sense, for the US. Washington should have few if any fixed alliances, allegiances, or even adversaries.

Instead, Trump believes that everything comes down to the art of the transaction, with countries that spend their money the way he wants them to getting more than countries that don't. That sounds appealing on the surface; every American wants to believe that his or her government is doing all it can to benefit them in a material way while keeping US troops from fighting and dying to protect countries that won’t do that themselves.

The problem is that foreign policy is too complicated to be reduced to a simple question of dollars and cents, and viewing the world solely through that lens is profoundly dangerous.

If Trump were to put his own stated polices into place, four foreign policy crises — two economic and two military — would be almost certain to erupt. Trump’s response will say a lot about the kind of leader he will be, and a lot about how his new administration will interact with an unstable and unsettled world.

Does Trump actually force Mexico to build a giant border wall?

We all know the line: "Build the wall, and make Mexico pay for it."

It’s a gigantic, nigh-impossible project — one that would undoubtedly be extremely expensive. "Trump is pledging the largest infrastructure project since the U.S. highway system — perhaps the most significant infrastructure project since the Erie Canal" Kriston Capps writes at CityLab. "It’s a moon-shot without a rocket."

Perhaps this is why President-elect Trump has insisted Mexico will pay for the wall. Yet Mexican President Enrique Peña Nieto has been very clear that his country, in fact, will not pay for a border wall between the two countries.

So what to do? One solution, as Trump has outlined it, will be to coerce Mexico to do it with economic pressure. Specific measures Trump has floated include:

Impound all remittances (money sent home by immigrants) from undocumented Mexican workers. Slap a high fee on Mexican CEOs and diplomats looking to visit the United States — or even ban them altogether. Slap a separate fee on border crossing cards to make legal crossing expensive for Mexicans. Slap a third fee on NAFTA worker visas. Slap a fourth fee on entry to US ports from Mexico. Imposing tariffs on Mexican goods and slash US foreign aid to Mexico.

This is a recipe for an economic crisis — Mexico is one of America’s most important trading partners — and a diplomatic one. Peña Nieto’s government would be under tremendous domestic political pressure not to cave, and global powers would almost certainly take Mexico’s side.

But this is the cold logic of the wall. If Trump wants to use it as a means of punishing Mexico for unauthorized immigration, this is what that will entail.

Another way out would be to settle for some kind of compromise position: Mexico erecting a smaller fence on some portion of the border, for instance. This is an idea that Trump surrogates floated during the election, though they were light on specifics about how it would work.

If so, this would be a major test of Trump’s braggadocio about making "good deals." Can he find a way to strike an agreement with Mexico that satisfies both him and his hardest core supporters?

Would Trump turn Eastern Europe over to Putin?

Trump campaigned on the idea of working to improve ties with Putin, who the new president has praised as a strong leader who could be a willing and capable partner in the fight against ISIS and other Islamist militants. He’s also said that the US would only defend NATO allies from a Russian invasion if the countries spent more on their militaries.

On its face, neither idea seems unreasonable. Russia has a powerful military, and its intervention in Syria has helped President Bashar al-Assad markedly regain lost territory and beat back the rebels working to unseat him. Moscow has also a marked willingness to use force without concern for civilian casualties on the ground, which means Putin could theoretically order the kind of large-scale bombing campaign against ISIS targets in Iraq and Syria that the US itself would be loath to take.

But there’s a catch. The United States is formally bound by Article 5 of the NATO treaty to come to the aid of any NATO member who comes under Russian attack. If Putin decided to test the new president by sending his forces into a NATO country like Estonia, Trump would have to decide between standing aside and watching NATO effectively come to an end or sending in troops and risking an actual war with Russia.

Candidate Trump strongly hinted that he’d be fine doing the former. President Trump would be pushed to do the latter by other world leaders, lawmakers from both parties, and many members of the Pentagon’s top brass. It’s hard to imagine a US president sitting idly by as Moscow annexes a sovereign country and renders a decades-old military alliance obsolete. Then again, it was also hard to imagine Trump ever being put in position to be the one making that choice.

One potential early clue into the new president’s thinking: whether or not commander-in-chief Trump sticks with the Pentagon’s current plan to have about 4,500 troops, along with hundreds of tanks, armored vehicles, and other pieces of military equipment on the ground in Eastern Europe by next February. If Trump slows or cancels those deployments, Putin will celebrate — and he’ll have every reason to.

Does Trump start a trade war with China?

During the campaign, candidate Trump repeatedly argued that China was "killing us" on trade policy. Now, President-elect Trump will soon be in a position to do something about that — but his proposals risk truly dire consequences.

Trump argued that China's currency policies are hurting America's ability to export its products by making their goods artificially cheap, and that its loose intellectual property protections allow Chinese firms to steal American technology.

One proposed remedy of Trump’s is to take China to the World Trade Organization, which adjudicates claims of currency manipulation. But his more radical idea is essentially to use presidential authority to slap tariffs on Chinese goods — the rate might be as high as 45 percent — to force them to comply. This would make Chinese exports to the US much more expensive, and thus do serious damage to China’s economic growth.

The problem, though, is that China could retaliate in the exact same way, slapping similar tariffs on US exports to China. This is what economists call a trade war: Instead of cooperating and keeping trade open, countries punish each other in an attempt to get some kind of advantage.

Even economists who disagree on trade agree that such a war would be very, very bad for the US economy.

US airplane manufacturers like Boeing, for example, are based domestically and export a lot of planes to China. US electronics companies, like Apple, depend on China for access to rare earth metals (a key product in your iPhone). These companies just don’t employ people in factories that have been outsourced; lots of Americans work in their American plants or at their domestic offices.

This would suck a lot of money and jobs out of the US economy. One estimate, by the Peterson Institute for International Economics, suggested that the combined consequences of Trump’s trade war with China and proposed wall-related tariffs on Mexico would cost the US 4 million jobs and throw it into recession.

"The results presented in this analysis are a conservative assessment of the damage that the trade policies advocated by candidate Trump could wreak on the US economy," the Peterson analysts write.

So the question is: How serious is Trump about trying to bring China to heel?

Trump said he would "dismantle" the Iran deal. Could he?

The short answer is yes. The Iran deal is not a formal signed treaty, but rather a political agreement between Iran and the United States, the United Kingdom, the European Union, France, Germany, China, and Russia. Under the deal, Iran agreed to accept verified limits on its nuclear program in exchange for relief from strict sanctions on its economy.

President Trump, using his executive authority, could undo the Iran deal by reimposing those US sanctions on Iran. To do this, all Trump would essentially need to do is issue an Executive Order telling the US Treasury Department’s Office of Foreign Assets Control (OFAC) to reimpose the various economic sanctions on Iran’s government, financial institutions, and businesses that were lifted as part of the Iran deal.

This would effectively end the agreement, as the removal of the crippling financial measures was a major part of why Iran agreed to the deal in the first place. And Ayatollah Ali Khamenei, Iran’s supreme leader, has said that if the United States tears up the agreement, that Iran "will light [the agreement] on fire."

Trump has also said at times that he wouldn’t necessarily rip up the deal entirely, but rather that he would try to renegotiate in order to get a better deal. But the chances of Trump being able to actually do that are fairly slim. Few experts think the rest of the countries who signed onto the current deal would be willing to reimpose their own sanctions given how quickly they’ve worked to sign new trade deals with Iran.

The first sign of just how unlikely that is to be came Tuesday, just as Americans were heading to the polls, when Iran signed a sweeping $4.8 billion gas deal with the French energy giant Total. The New York Times reports that it was the first such deal Tehran inked with a world power since the sanctions were lifted.

If only the US were to reimpose its sanctions, Iran would be under significantly less economic pressure than it was when it finally came to the negotiating table in the first place.

So does that mean Iran would immediately resume its push to build a nuclear weapon? Not necessarily. Robert Einhorn, a former Iran nuclear negotiator at the State Department, has written that if the deal were to collapse, "Iran would build up its nuclear capacity, but it may do so gradually to avoid providing a justification for stronger sanctions or the use of force. Tensions would rise, but a military confrontation would not be inevitable and would depend on the pace and direction of Iran’s nuclear program."

Although the US’s European allies in particular would be unhappy if Trump were to break the agreement, doing so would almost certainly please both Israel and longstanding Arab allies like Saudi Arabia and the United Arab Emirates, all of whom see Iran as a near-existential threat and have long warned that the deal would ease Tehran’s path to a bomb.

Prepare for a bumpy road ahead

From ISIS to America’s erstwhile NATO allies, candidate Trump liked to talk tough and promise to shake up an international system that he sees as rigged against the US. Virtually the entire American foreign policy establishment rejected these ideas, seeing American strategy on these issues as (basically) wise and sensible.

Now, Trump will be president — and we are in uncharted waters. Never in the history of post-World War II America has there been such a gulf between what the experts and policy professionals in Washington believe, and what the president has said he will do. Nor has there been a president who, frankly, has demonstrated such little knowledge about the world. That makes it very hard to predict how much of Trump’s risky foreign policy he actually intends to follow through on.

But the political science research suggests that presidents generally follow through on their campaign promises (or, at least, try). Many of these issues — like building a wall or fixing American trade policy — were core to Candidate Trump’s message.

Moreover, foreign policy is an area where presidents have an extraordinary amount of direct control. So even if the GOP-led House and Senate dissent on issues like trade, they won’t be able to block President Trump very effectively.

So there is a very good chance that Trump’s ideas inherently dangerous — ones so scary that even talking about them on the campaign trail made allies from Eastern Europe to Asia rethink their understanding of the US — could end up happening. Already, the South Korean National Security Council has convened a special meeting to discuss the country’s security situation after the election.

It’s a new day for the world. A very, very, scary one.

Watch: How Donald Trump thinks about foreign policy