Thinking a bit about that F-35 crash off the coast of Japan. The worry voiced by some is that Russia and China might be zooming to recover it.
That's not the worry.
China successfully downloaded files on the F-35 and probably sold/traded them to Russia.
The worry is what happens when others see a chance to grab it.
If the sale with Turkey falls thru and Greece buys it. You can bet Turkey will be doing its best to get its tech thru a shootdown. I'm betting Iran would love to get ahold of a crashed Israeli example. Brazil isn't about that type of subterfuge but they'd take advantage of the tech if it fell into their hands.
France is WELL KNOWN for their industrial espionage and if they haven't already penetrated our systems for details then you can bet that everytime an allied nation flies they'll have snooper planes up soaking every ounce of info they can from the thing.
At the end of the day when thinking about this program all that's been done is to rush the end of stealth as being dominant in aerial warfare.
If many have it then its no longer unique. The more its "out there" the more likely countermeasures will be developed to counter it.
The reality?
This version of stealth will be obsolete before they've completed Block 4 upgrades.
