Tariff wars are often short. Their legacies aren’t.

Subscribe to enjoy similar stories. President Trump’s start-and-stop expansion of tariffs on trading partners has no analog in modern history. President George W.

Bush’s tariffs on steel products were in place for less than two years. Their impact on the economy likely lasted far longer. Designed to protect the beleaguered but politically influential U.S.

steel industry, the 2002 tariffs raised costs for companies that used steel in auto parts, metal stamping and more. Though the tariffs were rescinded the next year, the affected companies became less competitive moving forward as they tried to sell their own products abroad, said Lydia Cox, an economics professor at the University of Wisconsin-Madison. Businesses suffered.

Jobs disappeared. “The effects were really widespread," Cox said. Her research suggests they lingered for a half-decade after Bush’s tariffs were lifted.

President Trump’s start-and-stop expansion of tariffs on major trading partners has no analog in modern history. Yet the past can still be instructive. Previous trade disputes over everything from semiconductors to lumber to chickens have sometimes dragged out for decades, rattling international markets and boosting consumer prices.

None of the presidents who pursued those policies staked his agenda on protectionism to the same extent as Trump. His measures cover an array of products: beer from Mexico, Chinese-made toys and Canadian planes. President George W.

Bush’s tariffs on steel products raised costs for many companies. Economists fear that Trump’s approach could unleash forces that have unintended consequences extending far beyond his time in office. “This is the biggest change to tariff policy that we’ve seen in recent history," Cox said.