There are two kinds of trade wars: dangerous ones, and dumb ones. The former is the kind that risks hurting the economy, but has the chance of winning valuable concessions from trading partners and ultimately increasing the gains from trade. The second is the kind that hurts the country, even if it succeeds.
So far, unfortunately, much of President Donald Trump’s trade war has been of the latter variety. He has done two very unwise things — imposed tariffs on intermediate goods, and directed the trade war at U.S. allies.