Since entering office in 2017, President Trump has upended longstanding tenets of U.S. trade policy and launched the most aggressive set of new U.S. tariffs and trade restrictions since at least the Reagan administration in the 1980s. Actions include renegotiating the U.S.-Korea FTA (KORUS) and NAFTA, using “Section 232” of the Trade Expansion Act of 1962 to impose tariffs on most steel and aluminum imports into the U.S. in a bid to support U.S. smelters, using “Section 301” of the Trade Act of 1974 to impose tariffs on approximately half of U.S. imports from China, and threatening to use Section 232 to impose tariffs reportedly up to 25% on U.S. imports of automobiles.

The administration’s aggressive stance on trade has upended diplomatic relationships and prompted multinational companies to re-consider aspects of their global supply chains. It has also brought retaliation, including Chinese tariffs on most Chinese imports of U.S. goods. European countries and other U.S. allies affected by Trump’s steel and aluminum tariffs have also retaliated with tariffs of their own against imports of U.S. goods, with many of the retaliatory tariffs targeting perceived politically important constituencies in the U.S., such as U.S. whisky distillers, who are heavily concentrated in the home state of Republican Senate Majority Leader Mitch McConnell.

But Trump’s aggressive trade policies also began to deliver some successes in 2018, including a successful renegotiation of NAFTA, now renamed the U.S.-Mexico-Canada Trade Agreement (USMCA), a renegotiated Korea-U.S. FTA, and at least some willingness by European and Japanese officials to discuss greater market access for U.S. products. While many major U.S. importers and trade associations have complained about the tariffs, the tariffs continue to draw support from several of the key constituency groups that they are intended to assist, such as the U.S. steel industry.

While U.S. tariffs against imports from allies are seemingly driven largely by the Trump administration’s general protectionist bent, Trump’s trade actions against China reflect a broader set of concerns that is more widely supported by members of the United States congress and American experts outside of government. These include both longstanding U.S. concerns over Chinese trade practices and market access barriers, and growing U.S. geopolitical competition with China—what the Trump administration’s National Security Strategy, released in December 2017, refers to as the return of “great power competition.” These geopolitical concerns have been central to the administration’s recent aggressive efforts to block the deployment of Huawei telecommunications technologies in new “5G” mobile communications networks around the world, and in the administration’s increasingly vociferous opposition to China’s “Belt and Road Initiative" (BRI). And because of increased U.S.-China geopolitical competition, U.S. use of targeted trade controls, investment restrictions, potential targeted sanctions, and other measures against China, will likely continue even if, as is widely expected, Trump and President Xi reach a broad agreement on many trade issues in the coming months and reduce some of the tariffs that are currently in place.