TORONTO—How desperate is Justin Trudeau to keep NAFTA? Ask the Mexicans, now peering out from under the proverbial bus—where, you know, Trudeau pushed them. Pretty desperate. As they welcomed the Canadian prime minister to Mexico City on Thursday—and as they gamely extracted the Canadian-made stainless steel that had slipped between their shoulder blades, the Mexicans likely marvelled about this once or twice. "¡Tan encantador! ¡Muy guapo! ¡Tan despiadado!” they must have said, to themselves. Rough translation: “So charming! So handsome!