Tariff turmoil: It's not a trade war if nobody's fighting back

William Clayton, a businessman who served successive US presidents and became one of the chief architects of the Marshall Plan, was no fan of tariffs. He rated the barriers erected during the Great Depression as one of the great crimes of the century. So it's hard to imagine that Clayton, who believed that free trade was as important to prosperity as American aid and security guarantees, would remotely approve of Donald Trump's efforts to reshape commerce. The ongoing White House-engineered upheaval, which has pushed tariffs to levels unseen since the Smoot-Hawley law of 1930, will be costly—even if the full…