The book provides readers with a thorough analysis of the hostilities that took place in the area of the Anti-Terrorist Operation in 2014-2015. Who, when and under what circumstances made the crucial decisions concerning the hybrid war, how the almost destroyed in previous years Ukrainian army was restoring, what kind of role played the volunteer formations, which stopped the enemy's advance deeper into the country? An officer of the operational reserve and military expert Alexander Surkov received the information to cover these and a number of other important issues directly from those who led the troops, planned combat operations and took responsibility for the fateful events for the country from the very beginning.