This week, President Donald Trump and his deputies hit out at some of America’s closest friends, blasting a “dumb” refugee resettlement deal with Australia and accusing Japan and Germany of manipulating their currencies. Ties with Mexico have deteriorated to the point its government had to deny reports that Trump told President Enrique Pena Nieto he might send U.S. troops across the southern border. “When you hear about the tough phone calls I have, don’t worry about it,” Trump said to an audience of religious and political leaders at the National Prayer Breakfast, a yearly event in Washington. “The world is in trouble — but we’re going to straighten it out, OK? That’s what I do.”

The dilemma for officials globally is figuring out if Trump’s blunt style is simply a tactic to keep them off balance or the start of a move to tear up the rule book that has guided relations with the U.S. since World War II. In the mean time, allies have little choice but to prepare for the worst. The latest attacks came against Australia and Japan, even with Trump’s new Pentagon chief in the region to offer assurances about the U.S.’s commitment to security ties. The White House described Trump’s hour-long conversation with Mexico’s leader as “lighthearted.”

“For those of us like Australia, Japan or Korea, who have been dependent on that continuity, we have got to start thinking about a situation where the U.S. is much more self interested, and more more capricious on what it might do,” said Nick Bisley, a professor of international relations at La Trobe University in Melbourne. “Countries in the region have got to sit down and say those old arrangements can’t last forever.”

Trump’s willingness to publicly attack America’s friends in Asia marks a sharp contrast from the Obama administration, which sought to build a united front against China’s military and economic clout. Trump instead has suggested Asian nations should pay more for U.S. security and pulled out of a 12-nation Pacific trade deal. Earlier this week, Japanese Prime Minister Shinzo Abe pushed back on Trump’s accusations his country was gaming the foreign exchange market and hindering U.S. auto sales. Still, Abe has a bigger concern when he meets Trump on Feb. 10: Japan depends on the U.S. “nuclear umbrella” to protect it from China and North Korea.