Near the end of September, Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, and Gen. Curtis Scaparrotti, NATO’s Supreme Allied Commander, Europe, arrived in Warsaw for a meeting with their NATO counterparts as part of a three-nation European visit by Dunford that took him from the alliance’s eastern frontier to the Iberian peninsula. Russia had just completed Vostok-2018, its largest military exercise. The drills showcased a military modernization that Moscow has sustained despite bruising economic sanctions. Military intelligence officers monitored the exercises for signs that they might include field hospitals, a possible telltale indication that the mobilization was more than just a drill. No actual hostilities ensued, but such is the state of distrust today between the Western alliance and Russia.