Volodymyr Zelensky, Ukraine’s president, said on March 3rd that 16,000 people from around the world had already volunteered to join the International Legion, his newly announced branch of the army. That number includes many people from Ukraine’s post-communist neighbours, as well as 3,000 Americans. Despite the reluctance of Western governments to join in combat, it seems likely that their citizens will do so. What will Ukraine’s legion of foreign fighters mean for the war?

