For three days last week, dockworkers no longer dotted the terminals at ports across the U.S.’s eastern and Gulf Coasts. The short-lived strike ended after the U.S. Maritime Alliance, which represents the port operators, agreed to raise salaries, allaying fears that the walkout could inflict a multi-billion dollar hit on the American economy. But the episode has both highlighted the central role of maritime trade in the U.S. economy, and cast a light on long-standing inefficiencies at U.S.