Welcome to The Adversarial. Every other week, we’ll provide you with expert analysis on America’s greatest challengers: China, Russia, Iran, North Korea, and jihadists. Read more below.***North Korea Over the past few weeks, North Korea has carried out a series of profoundly destabilizing actions, including signing a mutual defense treaty with Russia, test-launching a suspected hypersonic missile, fortifying the border, and continuing to send airborne trash balloons to South Korea.The most significant development over this period was a visit by Russian President Vladimir Putin to Pyongyang that culminated in the signing of a DPRK-Russia Treaty on Comprehensive Strategic Partnership covering mutual defense, arms transfers, and sanctions evasion.