Over the course of only seven months, Turkey and Russia have gone from ranking each other as public enemy No. 1 to catching up as old friends. Turkish President Recep Tayyip Erdogan and Russian President Vladimir Putin seem to be treating the November 2015 shootdown of a Russian Su-24 by Turkish F-16s and the feuding that followed as an anomaly in an otherwise chummy relationship. As Putin said, "Our priority is to bring our relations back to pre-jet crisis level" -- basically to get past this ugly episode and have everything go back to normal. If only it were that easy....