“Ask yourself, who really puts the people’s interests first: the trading power that respects your sovereignty, or one that scoffs at it?” Mr. Pompeo said to an audience of business leaders at the Siam Society, a cultural organization in Bangkok.

“ “It cannot be the case that a nation uses protectionism to protect its own goods and uses predatory tactics to deny other economies the chances to grow.” ”

—Mike Pompeo, Secretary of State

Although Mr. Pompeo didn’t name China until later in his speech, his comments appeared to be a warning aimed at countries in this region that have sought to deepen ties with Beijing. Southeast Asia, which has a population of more than 600 million people, increasingly finds itself courted by both Washington and Beijing and pressured to take a side on vastly differing views on trade and security.

The region as a whole has sought to tread a path between the two powers. Some countries, such as Vietnam, have benefited from the escalating trade fight. Others that traditionally have been closer to the U.S., such as the Philippines, have pursued Chinese investment, or, like Cambodia, rejected American pressure to embrace democratic ideals such as a free press, rights to protest or fair and transparent elections. […]