I want to know the answer to the following question:
Why was the USAF forced to ground some of its squadrons in 2013?
All the background I'm provided with is that "The Commander of Air Combat Command, General Mike Hostage indicated that the USAF must reduce its F-15 and F-16 fleets and eliminate platforms like the A-10 in order to focus on a fifth-generation jet fighter future.". Is that enough to answer the question?