The summit in Geneva between Presidents Joseph Biden of the United States and Vladimir Putin of Russia was supposed to stabilize bilateral relations by demarcating areas and issues each side deemed so important that any hostile incursion would encounter a strong response. In the present-day situation of intense confrontation—which differs from the old Cold War pattern because of its fast mutation and fluidity—this pragmatic recognition of “red lines” appears to make perfect sense.
Putin’s Penchant for Drawing and Crossing ‘Red Lines’ – Jamestown