WASHINGTON — Once soft on Russia and hard on China, President Donald Trump rapidly reversed course in the last weeks, concluding there’s more business to be done with Beijing than with Moscow.

Trump’s evolving views on those two world powers have brought the U.S. back into alignment with former President Barack Obama’s pattern of “great power” politics. Though Russia critics welcomed Trump’s newly hardened tone, there’s less enthusiasm from America’s allies in Asia, who fear the U.S. could overlook China’s more aggressive posture toward its neighbors.

It may be that Trump, the businessman-turned-world leader, is discovering China’s transactional approach to foreign relations is better suited to achieving his own goals. Chinese leaders have sought a U.S. relationship based on the two powers respecting each other’s spheres of influence and not intervening in one another’s internal affairs.

Such a balance-of-powers approach had been Russia’s traditional stance. Moscow still wants Washington out of its backyard, but Russia’s alleged campaigns to influence the U.S. presidential election and upcoming votes in the heart of Western Europe have made it harder for American officials to take the offer seriously. Russia’s support for Syrian President Bashar Assad and Trump’s newfound commitment to militarily countering any chemical weapons attacks also is proving hard to square.

Also, Trump and Russian President Vladimir Putin’s shared tendency toward nationalist, “don’t-mess-with-us” rhetoric may be putting the pair on a collision course.

The sudden U-turn has been head-snapping for people around the world, despite Trump’s self-professed penchant for unpredictability and willingness to adapt to changing circumstances.

As the Republican presidential nominee, Trump praised Putin repeatedly as a strong, “very smart” leader. Trump dismissed America’s Russia hawks as “stupid people or fools” and predicted under his leadership that the Cold War foes would “work together to solve some of the many great and pressing problems and issues of the world.”

Trump’s gestures to Moscow even fueled perceptions that his campaign and Russia were colluding to help him get elected — a possibility the FBI is now investigating.

“Frankly, if we got along with Russia and knocked out ISIS, that would be a good thing, not a bad thing,” Trump told a radio host in October, citing his still unrealized goal to have both countries cooperate to defeat the Islamic State group.

This past week, it was the opposite message, as the U.S. and Russia feuded about Syria.

“We’re not getting along with Russia at all,” Trump said. “We may be at an all-time low.”