At the start of the full-scale invasion, Oleksandr joined the Territorial Defense Forces, leaving his role as third mate in the merchant fleet. He served as an air defense platoon commander, taking part in operations in Bakhmut, Avdiivka, and the Kharkiv region.

In 2024, he was appointed Deputy Chief of Air Defense of the 3rd Assault Brigade, leading the development of a modern air defense system and integrating short-range radars and UAVs. Following the formation of the 3rd Army Corps, Oleksandr became Deputy Chief of Air Defense on the corps level.

Under his command, the 3rd Army Corps currently destroys over 4500 UAV targets monthly.

Drawing on both his seafaring background—which trained him to make rapid, precise decisions — and his combat experience on the battlefield, Vorobiov has been able to introduce new technologies and innovative methods. His leadership has significantly enhanced the Corps’ effectiveness in countering enemy air forces.