Publicly, the Calderón and Obama administrations have continued to paint a rosy picture of the U.S. and Mexico marching side by side to defeat the common adversary of drug cartels. But as revealed in WikiLeaks cables and offhand comments by officials on both sides of the border, tensions are growing. U.S. officials complain that they cannot completely rely on Mexico’s institutions — and this concern is exacerbated when their lives are on the line. For their part, Mexicans protest that they suffer from failed American policies on drugs and guns. The Obama Administration’s recent refusal to fast-track new reporting requirements for assault-weapon sales along the Mexican border only added to their frustration.