Russia’s invasion of Ukraine was a deeply flawed military operation, from Moscow’s assumptions about an easy victory, to a lack of preparation, poor planning, and force employment. Less attention has been paid, however, to Russian force structure and manpower issues as a critical element now shaping outcomes in this war. Plans rarely survive first contact with an opponent and militaries invariably must adapt, but strategic force structure choices can prove decisive. Force structure reveals a great deal about a military and its assumptions of what wars it plans to fight and how it plans to fight them.