Vast and global “black markets”—what national-security practitioners call shadow economies—are no longer peripheral nuisances but core strategic terrain. Trade executed outside regulatory, taxation, and enforcement frameworks prolongs wars, defangs sanctions, frays alliances, and helps rogue governments and groups survive and thrive. These flows have long been treated as problems for law enforcement, but military and defense policymakers and planners must increase their efforts to account for and stem them. Shadow trade enables regimes and insurgent groups to survive extreme pressure. Iran’s illicit oil exports help sustain the regime amid punishing sanctions. North Korea endures through complex illicit portfolios: counterfeit currency, arms smuggling, cyber theft, and forced labor. Russia earns billions by evading sanctions on oil, gas, and gold exports. Oil-smuggling states create front companies and “dark fleets” of tankers—Russia alone […]