President Trump and Turkish President Recep Tayyip Erdogan left the stage after a group photo taken at the NATO summit in the U.K. this month. Photo: peter nicholls/Reuters The declaration elicited an anxious reaction from U.S. Defense Secretary Mark Esper, who said it raised questions about Turkey’s dedication to the North Atlantic Treaty Organization. “They have that inherent right to house or to not house NATO bases or foreign troops,” Mr. Esper said. “But again, I think this becomes an alliance matter, your commitment to the alliance, if indeed they are serious about what they are saying.” Turkey, which has NATO’s biggest standing army after the U.S., has taken steps that have put it at odds with Washington and the rest of the alliance—including sending its army into northern Syria to fight a U.S.-allied militia and purchasing the Russian S-400 missile system . “It feels like watching a car […]