Asian carriers say failed harvests in the U.S. have reduced air shipments of high-value foods that have become a growing part of their business. As the tariff war grinds on, companies are revamping operations in ways that threaten to permanently shift trade flows. Shoemaker Crocs Inc. says it's building up inventory at a new distribution center in Ohio after boosting air shipments to meet demand for its plastic clogs in the first quarter. Ralph Lauren said it's shouldering higher inventories to reduce the use of air freight. "Freight export volumes from China may not recover to their pre-tariff levels," Cowen & Co. analyst Jason Seidl said in a May 8 report. "Many shippers have adjusted their supply chains to source goods from South Asia, South America, Mexico, and Canada or the U.S."