The Russian invasion in the morning of February 24 became a turning point in the past of the Armed Forces of Ukraine, which had to face a powerful aggressor army. Almost immediately, the general improvement process of the armed forces began, first taking in a crowd of volunteers and then besides mobilized. Thus, the process of fast improvement of the SZU has begun, and consequently besides structural changes, including the improvement of cascading tactical unions (brigades) of the alleged Reserve Corps and the formation of fresh units - battalions, regiments or brigades.