In recent months, North and South Korea have taken a wide variety of actions along their shared border that have increasingly threatened a long-standing, if unsteady, peace on the Korean Peninsula. These include military provocations and propaganda initiatives that, alongside longer-term shifts in national doctrine related to inter-Korean relations, have removed impediments to escalation. The Koreans are, of course, no stranger to fears of war, with the Korean War never technically concluded and the border area serving as one of the most heavily armed peacetime regions in the world for decades. Still, the recent trajectory of events on the peninsula brings a higher chance for military clashes that, even though they are likely to be limited and not escalate to full-scale war, would accelerate the formation of defensive blocs in Asia and create geopolitical ripple effects far beyond the Korean Peninsula....