We do not know if the period we are about to enter under the presidency of Donald Trump will be as turbulent as the 1910s, the 1930s, the 1940s, or even the 1960s. But it is a safe bet that if such turbulence were to recur in our lifetimes, it would happen under conditions like those of today—a superpower under radical and volatile leadership, geopolitical rivalries, a populist revolt, and a fragile global economy.

As we peer into that future, it makes little sense to talk of Trump’s foreign policy in terms of how it will cope with normal emergencies—North Korea testing an ICBM,  the Islamic State attacking the United States,  Venezuela collapsing, just to name a few. Yes, the National Security Council is disorganized. Yes, Trump is untested and impulsive. And, yes, chances are he will err, at least in the beginning. His team may learn from the experience, or they may not. But the real questions concern what unique crises they will face. What was previously unthinkable, but now plausible?

Trump has a core, visceral set of beliefs, dating back 30 years. He is skeptical of U.S. alliances. He is a mercantilist. And he is pro-Russian, with a soft spot for authoritarianism. His administration is deeply divided on fundamental issues of U.S. national-security policy, with several of his key cabinet picks disagreeing with their boss on all these matters. And Trump himself has a volatile personality, prone to attacking anyone he feels questions his personal success.

The foreign-policy crises that will shape the Trump era will tug on these threads— history is dominated by crisis and discontinuity, not steadiness or incrementalism, after all.

1. Putin’s big gambit. For Vladimir Putin, Trump’s presidency offers the opportunity of his lifetime. Trump dislikes NATO, admires Putin, wants to appease Russia, and is at war with his own intelligence community. But Putin’s optimism must be tempered by his knowledge the window of opportunity will remain open for only a short time before slamming shut. Trump’s position is brittle. He could be impeached or tamed by the establishment. He has persuaded virtually no one of consequence to adopt his pro-Russia view. In fact, bruised by Russian interference, many Democrats and Republicans may very well decide they have a new reason to fight another Cold War.

Now, Putin must be wondering how to take advantage of the Trump window to achieve something that can’t be undone by his successors. Putin fancies himself the heir of Peter the Great—how can he transform the world? Nothing infuriates him more than a European security architecture that denies what he sees as Russia’s rightful place as a great power. Surely the most tantalizing prize would be to break NATO by demonstrating that its mutual security guarantee, Article 5, is meaningless.

The challenge for Moscow is to exploit Trump’s pro-Russian policy without humiliating him to the point that he turns on Putin. That’s no easy task. But it is within his grasp. We can expect a challenge where the onus will be on Trump to act. It would go against every fiber of his being—to credibly threaten to wage war on behalf of an ally against Russia. It could tear apart the western alliance, taking the Trump administration down with it.

2. Fighting an economic war with China. China was one of the few countries in the world to welcome Trump’s success. Its government detested Hillary Clinton and her team, welcomed Trump’s criticism of U.S. alliances, and believed he was a pragmatist who would cut a deal. Xi Jinping, the leader of China, must be feeling whiplash now. Trump and his team—specifically his trade advisors Robert Lighthizer and Peter Navarro, and strategist Steve Bannon—believe China is waging an economic war against the United States through currency manipulation, the use of state-owned enterprises, and limiting market access, and want to retaliate in kind. As Trump advisor Anthony Scaramucci told the World Economic Forum in Davos, Trump believes the United States can fight and win an economic war with China. The United States may be hurt by the aftermath, but China will be hurt more. And it will yield. Or so the argument goes.

A U.S.-China economic war would be a catastrophe for both countries, for Asia, and for the global economy. But it would be a crisis of Trump’s choosing. The Trump administration is willing to pull every lever and use every economic and geopolitical weapon, including Taiwan, to bludgeon China into submission. For Xi, this must look like an existential threat. Xi, of course, is not blameless. He has pioneered an economic nationalism that has stoked tensions. But Trump’s position will be widely—and correctly—viewed as reckless and counterproductive.

This also presents Beijing with strategic opportunities. The rest of Asia will not react kindly to an economic war on their largest trading partner. Trump’s hostility to alliances raises questions about the reliability of the U.S. security guarantee. And he will struggle to deal with Chinese retaliation, either in kind or geopolitically in the South China Sea. Asian nations will also worry that Trump will cut a deal with China—whereby Beijing makes economic concessions in exchange for preserving its sphere of influence—that would destroy the regional order.

3. A trans-Atlantic split. America’s Asian allies—South Korea and Japan in particular—responded to Trump’s election by trying to cozy up to him. German Chancellor Angela Merkel stayed silent, as did many other European leaders. Trans-Atlantic friction is all but assured. Trump’s actions on climate change, a real phenomenon he doubts; Russia, a country he likes; and human rights, a concept he seems to dismiss, will upset them. If he tries to stoke the fires of anti-EU nationalism, he will anger European governments even more. And then there is the political calendar: France and Germany have elections later this year, and it is highly likely that the next leaders of both countries will criticize Trump during the course of the campaign.

How will Trump react if they do? Will he write it off as politics as usual, or will he take to Twitter to vent? What will he do if they criticize him while in office? If hundreds of thousands of Europeans demonstrate against him? Will he ignore the protests and rededicate himself to working with Europeans on matters of mutual interest, or will he denounce his allies and perhaps pull out of NATO in a fit of pique?

These aren’t the only potential calamities Trump will face. He must decide how to make good on his promise of backing Bashar al-Assad and Russia in Syria without empowering Iran. He will face problems with Mexico. There will be unexpected crises. But the real dangers will emanate from the logic of his own administration—particularly his worldview and his personality. Trump is trying to do something that no other president ever considered. He wants to undo the liberal international order the United States built and replace it with a 19th-century model of nationalism and mercantilism. Measured in terms of great-power peace, prosperity, and freedom, the liberal order was the most successful international order the world has ever known. Its unwinding cannot, and will not, be pretty.