Russia's renewed invasion of neighboring Ukraine in February 2022 marked the start of Europe's deadliest armed conflict in decades. After a steady buildup of military forces along Ukraine's borders since 2021, Russia invaded Ukraine on February 24, 2022, with Russian ground forces attacking from multiple directions. This book addresses Russian and Ukrainian military and intelligence aspects of the war. It provides an overview of the conflict, including the run-up to the invasion, the performance and conduct of the Russian and Ukrainian militaries, possible Russian intentions, and recent developments on the ground. Prelude to Invasion: Military Buildup and Force Posture Initial Invasion Analysis of Russia and Ukraine's Initial Military Performance Russian Performance Ukrainian Performance Possible Russian Intentions and Expectations 9 March-May 2022 May-September 2022 Kherson Region Offensive Kharkiv Offensive War Crimes Outlook