This month the CEO of Rostec, a giant Russian state-owned defense company, claimed it had developed a new coating that could make soldiers or tanks invisible. Sergey Chemezov told TASS that an “invisible helmet” covered in the advanced material would be displayed at a trade show. But experts say that while light-bending invisibility cloaks made of metamaterials are (theoretically) possible, they are many years away from being realized. Invisible tanks—let alone invisible helmets—are unlikely.

Although Russia has come up with some surprising new high-tech weapons over the years—hypersonic missiles, mobile high-power lasers, nuclear-powered torpedoes and combat robots to name a few—much of Russia’s boasted high-tech arsenal has proven either wildly exaggerated or completely imaginary.