Complex sentence: In June 1952, the 10th Special Forces Group (Airborne) was formed under Col. Aaron Bank, soon after the establishment of the Psychological Warfare School, which ultimately became today's John F. Kennedy Special Warfare Center and School.
Split into simpler sentences: In June 1952, the 10th Special Forces Group (Airborne) was established under Col. Aaron Bank. Concurrently with this was the establishment of the Psychological Warfare School, which ultimately became today's John F. Kennedy Special Warfare Center and School.