For a time, it seemed Russia was steaming toward fielding real fifth-generation stealth fighters, a development with serious security implications, based on the nation’s aggressive posture toward NATO and America’s reliance on air power in its style of warfare. As time wore on, however, cracks in Russia’s advanced fighter program began to show, culminating in India backing out of its agreement with the Kremlin for reasons that have been kept private (but were rumored to be based on the platform’s lack of actual stealth capabilities).

Today, the Su-57, Russia’s long-touted fifth-generation fighter, looks as though it will likely exist only as a token fleet, with a dozen or so of the serialized jets on order in the coming years and only one complete platform equipped with the engine intended for the fighter. The Su-57, like so many other Russian defense initiatives, may have brought a great deal of press coverage, but ultimately afforded the nation little-to-no strategic capabilities whatsoever.

Now, another high-profile Russian weapons program, once touted by Vladimir Putin as the future of Russia’s military capabilities, appears doomed to the same fate. The nuclear-powered cruise missile, the Burevestnik, now appears to be too expensive to ever field in serious numbers, and that’s assuming Russia ever manages to make it work.

Putin first brought the Burevestnik to the world’s attention in a public address delivered last March, in which the Russian president discussed a number of ongoing “advanced” weapon systems programs. The cruise missile itself relies on a nuclear propulsion system instead of the traditional solid or liquid fuel stores, theoretically allowing it to achieve supersonic speeds and stay airborne essentially forever. According to Putin, this incredible range would allow the weapon to more easily circumvent missile defenses on the way to its target.

However, each test of the platform has been a failure, that is, except for the most recent one which was publicly credited as a “partial success.” It’s not clear what part was successful, though, as the missile still failed to fly under nuclear propulsion.

Now, U.S. intelligence sources allege the missile has proven too expensive for Russia to field in any reasonable numbers, and more pressing, it appears to still be more than a decade away from becoming operational. So far, the longest test flight of the missile has been just two minutes, a far cry from Putin’s claims of forever, and managed to cover just 22 miles before crashing into the ocean. The failure seems to be consistently surrounding the nuclear propulsion system’s failure to engage when transitioning away from the traditional propulsion system that carries the missile for its initial launch.

Putin once touted the Burevestnik as “invincible,” but like the Su-57 or Russia’s capable T-14 Armata main battle tank, the nation’s struggling economy likely won’t be able to support ten more years of development for a missile platform that will likely be too expensive to mass produce. Instead, this missile will likely join its tank and fighter counterparts on the Kremlin’s back burner, where they’ll maintain a small number of each to stay relevant in defense conversations.

It would seem that the most potent means available to the U.S. and its NATO allies to defend against advanced Russian weapons programs is to just let them run their course. Russia’s economy continues to serve as its military’s Achilles heel, and has a knack for defanging both practical and impractical defense programs alike.