Every new occupant of the White House has his — still, unfortunately, "his" — way of looking at the world. America's allies, friends and rivals have always adjusted to these shifts in worldview. But so far they've been relatively straightforward. Some presidents have sought to extend democratic values, others to fight grand strategic battles. The last swore not to "do stupid stuff." Adjusting to U.S. President Donald Trump won't be that easy.
Trump's foreign policy, especially when it comes to Asia, is both predictable and unpredictable. It's predictable because he has repeatedly indicated that he questions America's traditional role as the guarantor of regional security. And it's unpredictable because no one knows what aspects of that role might be abandoned or negotiated away.
The nuclear umbrella in Northeast Asia? Support for freedom of navigation in the South China Sea? A continued U.S. troop presence in Afghanistan? Trump will want to prove that he is, in fact, a deal-maker — and all anyone can assume is that everything is now a bargaining chip.