It was a rude awakening for Joaquin Hernandez Galicia, the strongman behind Mexico's oilworkers union. At about 9 a.m. last Tuesday, scores of federal police officers and troops surrounded Hernandez's heavily guarded house in Ciudad Madero, northeast of Mexico City. Whether authorities first attempted to arrest Hernandez without force is unclear; what is beyond dispute is that the lawmen used a bazooka to blast open the front door. When the battle was over, a federal agent lay dead and Hernandez and about a dozen other union officials and bodyguards were under arrest.
Immediately after the raid, the government announced it had...