MOSCOW boasted it had a new world-beater: The Su-57 stealth fighter. It was smart. It was sneaky. It was lethal. Turns out, it’s none of those things.

It’s been a long, expensive road.

But the gamble Russia took in developing its first stealth fighter has failed.

It promised much: the ability to sneak up on opposing bombers and fighters unseen, to see them first, to shoot first …

Then reality hit home.

Engine troubles. Questionable stealth. The abandonment of the project by partner India. A credit crunch thanks to international sanctions over Russia’s invasion of Crimea.

THE Su-57: What we know about Russia’s most modern stealth fighter

Now, the combat jet touted as being able to take on — and beat — the US F-22 ‘Raptor’ stealth fighter and F-35 ‘Lightining II’ strike fighter has been unceremoniously dumped.

Some 11 examples have been built over the past 10 years. Each taking the integration of advanced stealth, electronics, engine and integration technologies one step further.

“The plane has proven to be very good, including in Syria, where it confirmed its performance and combat capabilities,” Russian Deputy Defence Minister Yuri Borisov said on Russian TV.

In the end, it wasn’t good enough.

Not that Moscow can admit that.

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“The Su-57 is considered to be one of the best aircraft produced in the world. Consequently, it does not make sense to speed up work on mass-producing the fifth-generation aircraft.”

So the prototypes are a dead end. There will be no mass-produced Su-57.

Instead, advances made and applied to the new airframe will likely be partially grafted on older aircraft, such as the Su-35.

Western analysts have long cast doubt over the Su-57’s true ‘fifth generation’ stealth fighter status.

It was big. It could carry an impressive array of anti-air and anti-ground weapons. It was also super-manoeuvrable.

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But does not appear to have succeeded at combining these attributes with being stealthy. And the ability of its engines to sustain high speeds for long periods of time was in doubt.

President Putin at first promised several squadrons of the advanced fighter would be operational in the 2020s. Then the order was cut back to a few dozen production models.

Now, there will be none.

THE J-20: What we know about China’s most modern stealth fighter

This leaves Russia at a considerable disadvantage to US, NATO and other Western-allied nations now fielding the F-35 stealth fighter. And China late last year declared its first stealth fighter — the J-20 — to be in operational squadron service.

How Moscow will manage this setback is yet to be seen.