If F35 turns out to rubbish, we could always take a look at the Japanese F3:
Japan Ready For Next Fighter Engine Core | F-3 | TRDI | IHI Corp. | Defense content from Aviation Week
If they ever finish it, it might be awesome, ceramic turbine blades, etc.
It would be ironic if F35, which is going to have to last a veeeery long time given how much money is being spent on it, gets immediately obsoleted by a home-grown Japanese design.
And if they're going it alone they'd be beholden to nobody else. An enviable position... They're 'in' the F35 program but apparently are grumbling about unit cost increases. Who isn't? It'd be very easy to argue that the funding would be better spent on a home grown F3 that will produce a lot of dual use (and commercially valuable) technology. Especially as they 'like' grand engineering projects like that.
It will also depend on whether their strategic nerve holds; F35 may be closer to being in service.