The price of oil has increased, making the Federal Aviation Administration's plan to reduce flights at Chicago's O’Hare International Airport moot due to the surge in demand. Jet fuel, the airlines' biggest expense after labor costs, has more than doubled since the Iran war, largely due to Iran's predictable closure of the Strait of Hormuz. This has led to increased demand for fuel, making many flights unprofitable and raising concerns about potential jet fuel shortages in Europe and Asia. Southwest Airlines is pulling out of the airport entirely, choosing to concentrate on Midway International Airport. Meanwhile, Korean Air will enter “emergency management mode” from April due to rising jet fuel prices. The most likely solution will be not to fly as often to as many destinations.