U.S. President Donald Trump's approach to foreign policy — based on tactics and transactions, rather than strategic vision — has produced a series of dazzling flip-flops. Lacking any guiding convictions, much less clear priorities, Trump has confounded America's allies and strategic partners, particularly in Asia — jeopardizing regional security in the process.

To be sure, some of Trump's reversals have brought him closer to traditional U.S. positions. In particular, he has declared that NATO is "no longer obsolete," as it supposedly was during his campaign. That change has eased some of the strain on the U.S. relationship with Europe.

But in Asia — which faces serious security, political and economic challenges — Trump's reversals have only exacerbated regional volatility. With so many political flash points threatening to trigger violent conflict, the last thing Asia's leaders need is another strategic wild card.