All signs seem to point to a budding bromance between the American president-elect and the Russian president. Donald Trump has praised Vladimir Putin as a strong leader, proposed reconciling with Russia so they can fight terrorism together, raised doubts about America’s commitment to NATO and the independence of Ukraine, and argued that America shouldn’t lecture other countries about democracy and human rights—all wonderful news for the Kremlin. Putin has been more restrained, describing Trump as “bright.” But his deeds appear more forceful than his words: U.S. intelligence agencies have accused Putin’s government of directing hackers to meddle in the 2016 election—perhaps in Trump’s favor, or at least at the expense of Hillary Clinton. Earlier this week, in a phone call, the two men discussed how to “normalize relations.” The Drudge Report captured the mood with a sketch of the leaders, looking heroic and macho in identical black blazers and white button-downs, over the headline, “TRUMP AND PUTIN: WE WILL DESTROY ISIS!”

But Fiona Hill, a Russia expert and Putin biographer at the Brookings Institution, isn’t convinced. Trump’s presidency will usher in “a stylistic, rhetorical change” in the U.S.-Russia relationship, she told me, “but I think it will come down to what it’s always been—where the Russians will get all giddy with expectations, and then they’ll be dashed, like, five minutes into the relationship because the U.S. and Russia just have a very hard time … being on the same page.”

Russia, she explained, has “always been an expansionist power—on the go all the time, not one to give up anything and concede anything—pretty much like the United States. It wants to have a veto, just like the United States has in its view, on international treaties and various issues. We’re going to have an awful lot of friction. And Trump isn’t exactly the most diplomatic of people. So I imagine he’ll fall out with his new friend Vladimir pretty quickly.”

Hill cited the Russia scholar Angela Stent, who has documented how, ever since the Soviet Union disappeared in 1991, “Periods of dialogue, progress, and optimism [in the relationship between Russia and the United States] have been followed by tense periods, standoffs, mutual criticism, and pessimism.” The legacy of the Cold War, the different ways Russian and American leaders view the world, and the shifting power dynamics between the two countries create structural tensions that are more powerful than the inclinations of whoever happens to be occupying the White House or the Kremlin.

Trump and Putin both take offense easily and hold grudges. Putin has positioned himself as the unpredictable, rule-breaking risk-taker among predictable, rule-following, risk-averse Western leaders, but it looks like he’ll now have to share that position with Trump. And critically, both men seem to prioritize making their own country great again above all else, meaning they’re unlikely to compromise when their national interests come into conflict. Long before Trump was promising to MAGA, Putin was vowing to MRGA. After becoming president in 1999, following the nation’s chaotic transition to democracy, Putin focused on rebuilding Russia’s military and economic power, and regaining respect from other countries. Russia was once “a great, powerful, strong state,” Putin lamented at the time. He pledged to bring back that glory.

These efforts to restore national greatness speak to a larger point: It’s not quite right to say that Russia and the United States—with their various conflicts in Syria, cyberspace, and Eastern Europe—are currently engaged in a new Cold War. Nor is it quite right to envision, in the coming years, a dynamic duo making the world great again. Russia and the United States are no longer the world-straddling superpowers they were during the Cold War, yet they’re still powerful enough to shape the world. And it’s hard to predict how two frenemies, each hoping to halt its own decline, will get along.

Russia’s apparent interference in the U.S. election, Hill noted, was one remarkable instance of Putin taking advantage of America’s newly evident weaknesses. But she disagreed with those who saw Trump’s victory as a successful Russian intelligence operation—as the product of sketchy ties between Trump’s campaign and the Kremlin, and embarrassing leaked emails from the Clinton campaign and Democratic National Committee.

The Russians didn’t create the dissent behind the election’s outcome, Hill argued. Rather, like all good propagandists, they “were riding the tide of dissent. They actually did an extraordinarily good job of reading the national mood [in the United States]. And that’s because they themselves are obsessed with polling. Putin’s got armies of pollsters always looking for any hints of trouble. And his is a populist presidency. Outside of the Moscow elite and a very small urban elite, Russia is one great big blue-collar country.”

Putin, she said, “has got a very important strategic perspective that people don’t give him credit for, and then he’s a tactical opportunist. … He has a clear strategy—[America is] his main opponent and he wants to outsmart us and outmaneuver us and block things that we’re doing that he doesn’t like—and he looks at every opportunity. This presidential election campaign provided those to him in spades.”

“Clinton was eminently vulnerable and eminently exploitable,” Hill continued. “Nobody invented Anthony Weiner, did they? And Putin didn’t make the decision for Hillary Clinton to have a private [email] server.”

These days, the United States is also eminently vulnerable and exploitable. The leaked emails not only turned the strengths of an open, technologically advanced country into weaknesses, but they also landed with a thud in a nation suffering from political corruption and polarization, low public trust in government institutions, and economic stagnation.

“The Russians mirror-image and think, ‘Ah, yes. The United States is about to collapse. Look, this is the Soviet Union of the late ’80s teetering on the brink: economic collapse, overextension of foreign wars … social dislocation, dissatisfaction with the system,’” Hill explained. Russia’s intervention in the U.S. election may have been less about helping Trump win or making Clinton lose than about undermining a wobbly United States, and its image and influence abroad.

And there’s no reason to think those efforts will stop with Trump. “It may be one thing to say, ‘Hey, bring out those 30,000 emails of Hillary Clinton’s,’” Hill said, referring to Trump’s plea to Russia during the campaign. “Does he want his own 30,000 brought out? … The Russians will play dirty against him as well, and presumably he’s had enough experience in cutthroat real-estate deals ... to know that.” Putin, she added, is “going to have to test and see what kind of mettle Trump is made of. [Trump is] uncharted territory.”

Hill acknowledged that Trump is unlikely to approach Russia the way past U.S. presidents have. “I tend to look at Trump as a real-estate mogul,” she said. “You look at a building and say, ‘I’m just going to tear that down and build up something new.’ He’s not exactly Mr. Preservationist.” Trump and Putin both think about foreign policy transactionally. Trump will likely withdraw U.S. support for Syrian rebels and permit Putin to shore up Russia’s ally, Syrian President Bashar al-Assad, so that the two countries can join forces against ISIS. Trump might even recognize Putin’s annexation of Crimea and remove sanctions against Russia over its intervention in Ukraine. The United States under Trump might turn inward, at least initially, leaving Russia to act largely as it pleases.

But at some point, the inherent tensions of the U.S.-Russia relationship will reassert themselves, and the bromance could buckle. What if Russia demands compensation from the United States for the damage sanctions inflicted on the Russian economy? Or reductions in the U.S. military presence in NATO countries near Russia? What if Trump demands that NATO members spend more on defense and those members actually comply, strengthening the military alliance that Putin so despises? What if Iran hawks in Trump’s administration advocate aggressive policies that anger Russia, which is allied with Iran in Syria? Trump, hemmed in by democratic checks and balances and public opinion (few Americans voted for Trump because of his position on Putin), could fail to deliver on his promises to the Kremlin, alienating the Russians. Putin, faced with an uncommonly friendly U.S. president, could find himself in trouble at home without a common enemy to mobilize his people against.

The Russians want “the old sit-down like they had with FDR at Potsdam and Yalta, working out what’s their piece of real estate and what’s ours,” Hill told me. “They want to have the U.S. acknowledge that they’re a great power and have the right to have a veto over things that they don’t like.” Trump, for his part, claims he’s no puppet of Putin’s. So how far will he go in consenting to Russia’s greatness?