Diplomacy: Like a guilt-ridden divorced dad, President Obama met with Mexico's President Calderon Thursday — and quickly caved in to all he asked. That's a jackpot for Mexico. But for the U.S., it's a mixed bag. The only reason Thursday's White House meeting between President Obama and Mexican President Felipe Calderon wasn't a complete loss for the U.S. was that some of the Mexican leader's agenda was to persuade Obama to respect free markets, honor U.S. treaty obligations, and help win Mexico's war spilling over the U.S. border. Up until now, Obama's paid scant attention to any of these issues,...