WASHINGTON—A U.S.-China Open Skies agreement is an unlikely prospect in the near future, participants in a panel discussion here said, although some on the panel did welcome the principle of such an agreement. The panel took place at the Hudson Institute think tank here to discuss the Open Skies diplomatic understanding announced last week between the U.S. and the United Arab Emirates (UAE). Like a similar understanding forged with Qatar, the deal keeps the U.S.-UAE Open Skies ...