The best kind of stealth is the stealth that nobody knows about. Now the plane is worth a fraction of what it was, strategically.

But how you gonna keep something like this a secret? Especially once it's built in any numbers?

One could probably even guess that the announcement was only made because the Chinese were found to be making their own version of it.

But on the other hand, the F-117 was operational for five years before it was officially disclosed. Whatever replaced the SR-71 has never been disclosed, but we're pretty sure it exists because the Department of Defense happily gave most of its SR-71s over to NASA.

Stealth is a procedure that reduces detectability through technology and tactics and secrecy, the last being the most important, because if the other guy doesn't know it exists, they don't know to look for it. We've long since had to give up on the last part (in most cases) because we can't keep anything secret for long, and it looks like the Japanese have the same problem.

in practice in serious numbers. Them announcing this is no different that the US talking about F-35 or the China with the F-35ish J-31 plane, or Russia with its PAK-FA. Everyone is doing stealth these days. I'm sure the really "cool" stuff being done by all nations is still kept super secret and hidden. I doubt we'll be hearing about Japan's time warping chronolaserbots.

With the limited space (for anything!) on the Japanese islands - just where would they keep such a thing under wraps? The US has it's Area 51, and I would guess Russia and China do too. But Japan would have a hard time keeping a new, big weapon like this from being seen.

The SR-71 community was a small one in the Air Force, so it lacked senior people with enough clout to keep it alive. Some one wanted to use the money for the SR-71 community for something else, maybe for the fighter community or space community, both of which are much larger and much more influential when it comes time to decide where the money is going to go.

Another consideration is that increases in surface to air missile technology have probably gotten to the point that even the SR-71 was going to become vulnerable.

But interestingly enough, I've heard the (keep it simple, stupid) U-2 has been pressed back into service when a quick turn-around is required; to Hell with the associated dangers. Prepping the SR-71 for flight on short notice was a maintenance nightmare, "You want it when?".

It's larger, with a more powerful engine and the sensors are configured to look "over" the border of another country without ever crossing into that country's airspace.

https://en.wikipedia.org/wiki/Lockheed_U-2

Even now the SR-71 remains a remarkable achievement. While it wasn't true stealth, it was designed with the smallest possible radar cross section so by the time it showed on "enemy" radar, it was far too late to scramble fighters to be in a position to intercept the SR-71 cruising at Mach 3+

https://en.wikipedia.org/wiki/Lockheed_SR-71_Blackbird

Japan wants the whole world to know about this, it's an engineering marvel (on paper at least) and this is the first homegrown fighter aircraft Japan has built in decades... It's a matter of national pride that they won't have to get their arms twisted by Washington to buy our 4th gen jets anymore...

Nevermind the fact that they'll be trying to *sell* these to other countries, so there's no benefit in keeping it secret (it's been well known about in aviation circles for awhile now)... This isn't the F-117 or B-2A, which were kept secret for years...

Instead of spending the money to develop stealth planes, a country could say that it had them and had already flown them over the territory of hostile neighbors. The neighbors would have to assume it was true.

(Joking)