Russian military intelligence at the start of the twentieth century -- Japan's war capability through Russian eyes -- The Japanese attack against the Pacific Squadron -- Russian military intelligence in the first months of war -- Inside the bastions of Port Arthur -- Russian military intelligence in the battles of Liaoyang and Shaho -- Realignments in Russian military intelligence before and after the Battle of Mukden -- The debacle in the Strait of Tsushima -- The dilemmas of Portsmouth -- Repercussions of the war : a thorny path of reforms.