U.S. tariffs are reordering world trade and may further impact the nation’s agricultural exports. While soybean exports to China are stalled as that nation redirects all of its purchases to South America, that has been a political position that ignores the lower cost of U.S. soybeans. However, the application of tariffs is also rearranging the economics of trade.  Washington accepted Brazil’s WTO challenge of its new tariff regime, and it will claim national security as their rationale. The new tariffs will remain regardless of how the WTO rules on the national security claim. Jurists in the case will have a real dilemma. If it concedes on the national security argument, then countries will more frequently invoke it as the...