The U.S. and Mexico already have relatively free trade, so
absent gunboat diplomacy to force Mexicans to buy more U.S. exports, all the U.S. can really do is restrict the amount of imports from Mexico by erecting new trade barriers.
Perhaps trade and warfare were equivalent back in the days of
gunboat diplomacy (a favoured U.S. strategy in Asia in bygone days), but
absent a willingness to engage in armed confrontation, today trade and warfare are fundamentally different.