Tensions between Russia and Turkey widened on Tuesday over the Russian bombings of Syrian rebels and multiple violations of Turkish airspace , which have deeply undercut Turkey’s goals in the Syrian civil war. “Our positive relationship with Russia is known,” President Recep Tayyip Erdogan said Tuesday at a news conference during a visit to Brussels. “But if Russia loses a friend like Turkey, with whom it has been cooperating on many issues, it will lose a lot, and it should know that.” Aside from blunt warnings, however, there appears to be little that Mr. Erdogan can do about Russia’s assertive military actions in Syria , which have upended his priorities to oust the Syrian leader, Bashar al-Assad , and establish a buffer zone […]