The U.S. Department of Commerce has imposed steep antidumping and countervailing duties—ranging from effectively 0% to an unprecedented 3,521%—on solar panels and modules imported from Cambodia, Malaysia, Thailand, and Vietnam, according to data released on April 22. The tariffs, which vary by exporter based on their level of cooperation with the U.S. investigation, mark a major escalation in trade enforcement efforts.

The targeted countries accounted for approximately $12.1 billion, or 80%, of U.S. solar panel imports in 2024, according to Trade Map data. While the duties aim to curb unfair pricing and transshipment practices, they are expected to trigger a broader realignment of global solar supply chains and could pose long-term challenges for the U.S. domestic solar manufacturing sector—despite offering near-term protection.

At the center of the decision are Chinese-owned companies operating in Southeast Asia, effectively making the tariffs a new flashpoint in the ongoing U.S.-China trade rivalry. Cambodia, which faces the harshest penalties, is likely to see its emerging, Chinese-dominated solar sector crippled. Thailand and Vietnam have been hit with firm but varied tariffs, depending on the exporter, with some firms retaining a narrow window for continued trade.

Malaysia emerged with the lowest penalties, positioning it as the least affected of the group, though the broader impact of the tariffs is still expected to be significant. Meanwhile, regional neighbors such as Indonesia and Laos may absorb some of the diverted manufacturing capacity, though they too could soon face similar U.S. trade measures.

The duties bring to a close a lengthy investigation originally launched in response to a complaint by U.S. manufacturers during the Biden administration. The announcement also aligns with President Donald Trump’s renewed focus on tariff-based economic policy as part of a wider push to reshape U.S. trade strategy.