The Trump administration’s tariff policy has bewildered business leaders, as the president ignores long-standing alliances to punish countries that he says are “screwing us on trade.” CEOs are bracing for more pain to come, as the White House has said that on April 2 the government will steeply hike tariffs against the “Dirty 15,” the 15% of its trade partners with whom the U.S. has the biggest trade imbalances.

While the White House has not been specific about which countries make up the Dirty 15, a look at current trade and tariff data offers some clear clues, as our chart below indicates.

What often gets lost in the melee is the fact that most of these trade relationships have always included tariffs. Under the rules of the World Trade Organization, most nations impose modest taxes on most imports; developing nations are often allowed to levy higher-than-average fees, to protect their own nascent industries. But when a country has both a trade surplus with the U.S. and higher tariffs than America’s, this administration may be more likely to see cause to retaliate—as Mexico and China know well, and as Vietnam, South Korea, and others may soon find out.

This piece appears in the April/May 2025 issue of Fortune with the headline “When big trade partners become big tariff targets.”

Which countries will get hit next by Trump administration tariffs? These trade partners could be targets