Four of the main retail groups in the United States — including the country’s and the world’s largest, Walmart — have highlighted in their respective second-quarter earnings presentations the complexities their businesses face due to tariffs imposed by the Trump administration. These tariffs have been the main topic of discussion for Walmart, Home Depot, Target, and Lowe’s — listed retailers that are already feeling, to a greater or lesser extent, the effects of this trade policy.As for results,...