U.S. foreign policy under President Donald Trump is the top risk to the global markets, according to a new Eurasia Group report released Tuesday.

“The world’s sole superpower was once the international trump card, imposing order to force compromise and head off conflict. Now it’s the wildcard,” the report concluded.

Trump will not be an isolationist and will intervene strongly when he thinks U.S. interests are at stake, the report said. As a result, his policy will be more hawkish and much less predictable.

U.S. foreign policy will be more akin to China, with narrow short-term agreements that are win-win for the two parties and “everyone else be damned,” said Ian Bremmer, Eurasia Group’s president, in an interview on Bloomberg.

Financial markets don’t appreciate that “this year marks the most volatile political risks environment in the postwar period, at least as important to global markets as the economic recession of 2008,” he said.

“Allies, especially in Europe and Asia, will hedge. Rivals like Russia and China will test,” the report said. For instance, China’s President Xi Jinping may overreact to the new U.S. stance because he cannot afford to look “weak and irresolute” ahead of next fall’s ruling Communist party congress.

In a separate interview on Bloomberg, former Treasury Secretary Lawrence Summer agreed Trump’s likely “truculent nationalism” was a leading risk to the global economy.

“The uncertainty premium on everything should go up,” Summers said.

German Chancellor Angela Merkel will likely win reelection in 2017 but will emerge as a weakened figure, the report said.

“This will leave Europe with no strong leadership at all — at a time when strong leaders are badly needed,” the report said.