Korean War:

General Ridgway was appointed Supreme Commander, Korea; he regrouped the UN forces for successful counterattacks, while General James Van Fleet assumed command of the U.S. Eighth Army. Further attacks slowly depleted the PVA and KPA forces; Operations Courageous (23–28 March 1951) and Tomahawk (23 March 1951) were a joint ground and airborne infilltration meant to trap Chinese forces between Kaesong and Seoul. UN forces advanced to "Line Kansas", north of the 38th parallel. The 187th Airborne Regimental Combat Team's ("Rakkasans") second of two combat jumps was on Easter Sunday, 1951, at Munsan-ni, South Korea, codenamed Operation Tomahawk. The mission was to get behind Chinese forces and block their movement north. The 60th Indian Parachute Field Ambulance provided the medical cover for the operations, dropping an ADS and a surgical team and treating over 400 battle casualties apart from the civilian casualties that formed the core of their objective as the unit was on a humanitarian mission.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". Under the guidance of Generals Van Fleet and Ridgway, joint forces were able to achieve what goal?
depleted the PVA and KPA forces