Complex sentence: The first airport in Pyongyang was located on the east bank of the Taedong River but soon after World War II, there was a need for a newer airport and the Sunan International Airport was constructed.
Split into simpler sentences: The first airport in Pyongyang was located east of the Taedong River. However, after World War II there was a need for a newer airport, and Sunan Airfield was constructed.