President Trump’s recent announcement that he intends to impose tariffs on an additional $200 billion in Chinese products is simply the latest indication of his determination to dismantle the international economic order that the United States put in place at the end of World War II. The governing premise of that order was that trade among states should be regulated by rules, reciprocity, and restrictions on protectionist measures. From his rejection of the Trans-Pacific Partnership and threats to withdraw from NAFTA to his attacks on G7 partner nations and placing punitive tariffs on an ever-expanding array of foreign goods, Trump has launched an assault on an economic order that has underwritten America’s global dominance over the past 70-odd years and arguably overseen the greatest burst of wealth production in recorded history.

The standing room-only crowd that attended the National History Center’s congressional briefing on the history of trade policy late last month reflected the widespread anxiety about these developments and desire to make sense of them. The congressional staffers and interns who packed the room were treated to two starkly different interpretations of America’s history of trade policy and assessments of its implications for the current moment—one of them making a case for the merits of the rules-based system that has governed global trade since 1945, the other arguing that this system has subordinated America’s economic interests to its foreign policy objectives.

Susan Ariel Aaronson, an economic historian at George Washington University and author of numerous books on trade policy, offered a critique of protectionism and defended the international system of trade that Trump has attacked as “unfair” to America. Aaronson acknowledged that “protectionism became the American way” in the 19th century, but argued that its impact was largely negative: protectionism distorted markets, privileged special interests over the public’s interest, and created an unaccountable system of “log-rolling” involving the exchange of political favors....

A contrasting perspective was offered by Alfred Eckes, an emeritus professor of history at Ohio University and member of the US International Trade Commission from 1981 to 1990 (chair during 1982–84). In his written remarks, Eckes characterized the trade policy debate as a struggle between “Wilsonian globalists,” who favor the current rules-based, multilateral system of trade, and “grassroots skeptics” such as himself, who believe that this system has placed an unsustainable financial burden on the United States. The main measures of that burden, Eckes argued, are the national debt, which currently exceeds $21 trillion, and the deficit, which reached $466 billion in 2017....