Boeing might seem like the target of China’s tariff ire. But it is those who use the Boeing planes—airlines—that are the most immediately vulnerable.

Washington and Beijing’s tariff lists are just proposals for now. Nothing changes right away. The Trump administration has given until May 22 for businesses to chime in with comments and has another 180 days to decide whether to move ahead. China put no timeline on its retaliatory measures, including tariffs on planes. Negotiations seem likely.

Yet...