One of President Obama's applause lines is that his climate tax policies will create new green jobs "that can't be outsourced." But if that's true, why is his main energy adviser floating a new carbon tariff on imports? Welcome to the coming cap and trade war.

Energy Secretary Steven Chu made the protectionist point during an underreported House hearing this month, when he said tariffs and other trade barriers could be used as a "weapon" to force countries like China and India into cutting their own CO2 emissions. "If other...