This report analyzes the evolving dynamics within Russia's security sector since the invasion of Ukraine in February 2022. It highlights that President Vladimir Putin's decision-making power is concentrated in a small group of individuals from both formal and informal institutions in Russia. While Putin traditionally relied on Kremlin security institutions, he has increasingly turned to private and informal entities like the Wagner Group and oligarchs to finance and support the war. This shift has raised concerns about the stability of Putin's leadership and the reliability of his allies.