Hypersonic or just overhyped? Amid Russian failures, U.S. doubles down on super-fast missiles

The long-awaited battlefield debut of hypersonic weapons was largely a bust, but experts say it had much more to do with who pulled the trigger than underlying problems with the technology.

Russia’s hypersonic Kinzhal missiles have failed to hit their targets in Ukraine on multiple occasions. In many cases, they have been intercepted by the tried-and-true U.S.-made Patriot missile defense batteries fielded by Ukrainian forces.

Moscow boasted for years that its hypersonic weapons program was miles ahead of the Pentagon’s and that its super-fast, maneuverable missiles could evade even the world’s...