Complex sentence: He was re-assigned to Nairobi, Kenya in August 1990, as the UN evacuated non-essential staff, but traveled back to Mogadishu that December despite his orders to see rebels marching against the capital city.
Split into simpler sentences: He was re-assigned to Nairobi, Kenya in August 1990, as the UN evacuated non-essential staff. He traveled back to Mogadishu that December despite his orders to see rebels marching against the capital city.