President Barack Obama has spent his two terms in office working to build closer ties with China while seeking to isolate and punish Vladimir Putin’s Russia.

Eight years later, Moscow is subject to painful US sanctions and continued public criticism from Obama and his aides. Beijing is a key economic partner that has at times served as a conduit to the rogue regime in North Korea.

To a large extent, that’s because the two countries have acted fairly differently in recent years. Russia’s 2014 invasion of Ukraine, 2015 bombing campaign in Syria, and 2016 hack of the US election convinced the administration that Russia was a threat to the international order — a power unwilling to play by the rules. Despite its aggressive moves in the East and South China Seas, Beijing has been far less confrontational, and far more willing to negotiate with the West in good faith on long-range issues like climate change.

Team Trump sees things totally differently.

President-elect Donald Trump sees Putin not as a threat to Western norms but as a tough and capable leader and potential partner in fighting radical Islam. China, in his eyes, is a threat to the US economy — responsible for the loss of massive numbers of American jobs — and a country that US presidents have been far too soft on for decades. By this analysis, Russia is the potential partner, and China the potential enemy worth confronting.

“China is the biggest state adversary in Trump’s mind,” Patrick Cronin, the senior director of the Asia-Pacific Security Program at the left-leaning Center for a New American Security, tells Vox. “It's not Russia. It's China.”

The differing worldviews have been on public display in recent days. Obama used his press conference at the White House on Friday to suggest Putin was connected to his country’s cyberattacks against the US and belittled Russia. "They are a smaller country, they are a weaker country, their economy doesn't produce anything that people want to buy except for oil and gas and arms, they don't innovate,” he said. On China, he recommended respect for diplomatic tradition, cautioning against Trump’s indications that he would consider dropping Washington’s “One China” policy, the diplomatic understanding on the status of Taiwan that has underpinned US-Chinese relations for decades.

Trump, by contrast, has publicly castigated the CIA for its assertion that Russia ran a sustained hacking campaign designed to boost his chances of winning the presidency. And he’s been unrepentant about his tradition-breaking phone call with the president of Taiwan and language on revisiting One China. Beijing has responded by saying that the countries would have “nothing to discuss” on other issues if Trump tries to deviate from One China. And after China agreed to return an unmanned US Navy drone it seized on Friday — an act that led to a striking uptick in maritime tensions between the two countries — Trump tweeted: “We should tell China that we don’t want the drone they stole back.- let them keep it!”

What this suggests — though, knowing Trump, we can’t be sure — is that we’re about to see a massive about-face in great power politics. Obama’s basic policy — work with China, isolate Russia — is about to be flipped on its head. The US is going to start working with Russia on a raft of issues, and start challenging China on a lot more. That could mean US policy reversals on a whole host of issues, from Syria to climate change to the US economy, with potentially major consequences for people around the world.

Get ready, in short, for some turbulence.

Trump’s China policy is a recipe for conflict

China watchers aren’t exactly sure what Trump wants out of Beijing.

His aggressive policies — proposing to impose a massive tariff on Chinese goods, for example — could simply be the result of instinctive hawkishness. By this interpretation, Trump sees China as a threat that will only respond to the threat of force.

Conversely, he could be trying to strike a deal with what he sees as America’s biggest rival. His aggressive policy proposals and rhetoric are opening bids designed to establish a stronger negotiation position down the line.

At this point, it’s impossible to tell which of these interpretations is correct. The reason is that, in either case, Trump’s opening moves would look the same: aggressive positions on areas where the US and China are at odds. And indeed, that’s what we’ve seen, with Trump openly talking about raising tariffs and considering the possibility of dropping the One China policy.

This means increased tensions between the US and China are inevitable, at least in the short term.

“Going back three weeks, [Chinese officials] were kind of guardedly optimistic, hoping that they could flatter Trump,” Aaron Friedberg, a China scholar at Princeton University, says. “In a way, he preemptively set the tone [for conflict] by doing what he’s done.”

China appears to be responding in kind. From heated rhetoric in the official state press to the recent seizing of an underwater American drone near the Philippines, Beijing is sending signals that it won’t be pushed around.

Trump will soon be in a position to respond. And while he hasn’t specified what he’ll do, exactly, to signal strength to China, it’s almost guaranteed that he will do something, if only to show that he’s serious about taking a hard line.

“We’re going to shake this thing up, color outside the lines, challenge the orthodoxy,” Cronin says, describing how he sees the Trump attitude. “The risk acceptance of Trump is much higher than Obama, who was famously risk-averse in dealing with China.”

There are all sorts of ways Trump could do this. Options, according to the experts, include:

Selling advanced weapons to other powers in East Asia, like Vietnam

Boosting the US military’s training mission with its Taiwanese counterparts

Escalating direct US military operations in areas of tension, like naval patrols in the South China Sea

Following through, even only partially, on the campaign threat to slap tariffs on Chinese imports

Each of these policies carries its own risk. Military measures, like arms sales or patrols, risk provoking some kind of Chinese counter-provocation — something more dangerous than merely seizing a drone. China could justify as this as a response to US moves, thus strengthening its overall position in East Asia.

“I’m worried about our long-term position in the region,” Friedberg says. “One of the things that’s concerned me about the way this has gone in the past couple weeks is that I think it’s going to enable the Chinese to put blame on the United States for doing and saying destabilizing things.”

US trade sanctions on China would directly damage the US economy, even if China doesn’t choose to respond by carrying through on its implicit threat to sell off some of the US debt it owns.

Since we don’t fully understand the Trump administration’s thought process, we can’t be sure which of these or the many other options for hurting Beijing he’ll pick. That means we’re in a period of dangerous uncertainty on a wide variety of deeply important global issues — and, indeed, on the fundamental nature of the most important bilateral relationship in the world.

How making nice with Russia could make the rest of the world worse

Trump’s well-documented affection for Moscow could also destabilize global politics. The policies that most logically follow from his overall view of Russia would upset established alliances and create incentives for Moscow to step up some of its more troubling behavior.

The biggest and most obvious action Trump could take to ease tensions with Russia is lifting sanctions on its economy, which, along with a plunge in global oil prices, have helped tip the Russian country into a recession since 2015. The sanctions were slapped on Russia in 2014 in response to its annexation of Crimea, a peninsula on Ukraine's Black Sea coast, and its backing of pro-Russia separatists in eastern Ukraine.

Lifting sanctions is something that can be done with ease — a president can lift sanctions by executive order, which means it can be done without Congress. It’s also an attractive option for Trump because sanctions are a prime example of a policy that has both significant material effects and enormous symbolic value: They’ve not only put a serious strain on Russian banks and oil companies but have also been the leading contributor to contemporary anti-American sentiment in the country. So lifting sanctions is a perfect way to turn over a new leaf in US-Russian relations.

Russia analysts say there’s a significant chance that Trump will lift sanctions shortly after taking office, but as with everything involving him, there’s always the caveat that his attitudes could change. He's already publicly mentioned that he’ll “look at” lifting sanctions, and his nominee for secretary of state, Exxon Mobil CEO Rex Tillerson, criticized them in 2014 after the measures led to the collapse of a multibillion-dollar Arctic energy deal with Moscow.

Lifting sanctions won’t just provide an economic boost to Russia; it will also implicitly endorse the country’s expansionist activities in Ukraine. Russia could in turn feel empowered to meddle in other countries with impunity. The consequences of this, much like those of Trump’s China policy shifts, are unknown — maybe they’d be nothing. But saying “we’re fine with you annexing territory” is certainly a dangerous signal to send to a leader as revanchist as Putin.

The second major opportunity for creating bridges with Russia is over the proxy war between the US and Russia in Syria. Russia’s air campaigns on behalf of Syrian President Bashar al-Assad since autumn of 2015 have helped reverse the dynamics of the conflict there, putting US-backed rebels against the Assad regime on their heels. The onetime opposition stronghold of Aleppo is almost entirely under government control, and Assad’s likelihood of staying in power in Syria is growing by the day.

The fact that it appears that Russia may have effectively “won” the proxy war for the future of Syria as Trump enters office might sound like a bad place to make a deal, but in fact it could end up being just the opposite. That’s because it would eliminate the biggest difference between the US and Russia — what to do about Assad — and then bring their putatively shared interests of defeating ISIS in Iraq and Syria back into the foreground.

“If Assad really is successful in wiping out the rebels, in a way, it makes the question of the differences in US and Russian approaches moot,” Yoshiko Herrera, a political scientist at the University of Wisconsin Madison who specializes in Russia, says.

Both the US and Russia have a national security interest in wiping out ISIS, and that’s what makes the scenario ripe for deals. Russia’s commitment to the cause could also relieve Trump of some of the burden of having a military presence in the region should the US and Russia both decide to invest in a sustained campaign against ISIS in the region.

US-Russian cooperation in Syria wouldn’t be without enormous challenges. Trump would receive huge pushback from critics in both parties who believe it would be unconscionable to allow the brutal Assad regime, stained with the blood of countless war crimes, to stay in power.

The Pentagon and CIA, meanwhile, could balk at the thought of sharing intelligence in the Middle East in light of mounting evidence that Russia used cyberattacks in a bid to tip the US election.

The third major domain in which Trump can relax relations with Russia is related to how he approaches NATO. The Cold War–era military alliance was formed to protect Europe from the Soviet Union, and today one of its roles is serving as a bulwark against Russian influence and expansionism. If Trump continues to criticize NATO or takes steps to substantively reduce American support for the alliance, that’s automatically beneficial to Russia.

“Previous to Trump, every incoming president has been a supporter and defender of NATO,” Herrera says. She believes that just with rhetoric, Trump can deal significant damage to the meaning of NATO and cause its enemies to make new calculations about the costs of attacking member states.

Under Trump, the US could theoretically devote less money to NATO’s budget, or be less inclined to participate in the installation of defense equipment or deployment of troops in Eastern Europe to deter Russia from pulling a repeat of what did with Crimea. All of this in turn makes Russia more relaxed and gives it more leverage over Eastern European states.

“Russia has been annoyed and threatened with the US for being the world’s police, for its very expansive foreign policy that reaches into many of Russia’s traditional areas of national interest,” Mariya Omelicheva, a scholar of Russian foreign policy at the University of Kansas, says.

If Trump takes actual policy steps back from NATO, combined with his musing about the alliance’s value on the campaign trail, NATO allies might start to think that the US can’t be trusted to defend them. Then they’ll start to wonder why they bother to adhere to this alliance in the first place — essentially calling one of the pillars of the postwar world order into question.