History really does have a way of repeating itself. Remember when the U.S. tried this before?
It was called the TFX and it was a fiasco. In the early 1960s Robert McNamara tried to achieve "cost savings" by forcing the Navy and Air Force to buy the same airplane. The Navy dropped out and the Air Force turned it into the F-111, a modestly successful aircraft.
The military tried it again in the mid-60's, more successfully this time as both the Air Force and Navy bought 5,000 F-4 Phantoms, one of the longest-running production airplanes of all time. But this time, the Air Force basically adapted a NAVY design and used it.
Now here we are with the F-35, which is looking more like a TFX and less like an F-4.