Why Russia’s ballistic missiles are increasingly getting through Ukrainian defenses

When Russia fires a ballistic missile at Ukraine, air-defense systems have only minutes — sometimes seconds — to detect and intercept the deadly threat.

The lack of time has left Kyiv and other cities increasingly exposed to devastating attacks by the missiles that come down so fast and so steeply that Ukraine says only the U.S.-made Patriot defense system can stop them. But Ukraine says it has too few batteries and interceptors to protect itself.

Unlike cruise missiles, which behave like pilotless planes, ballistic missiles are launched like rockets and then dive steeply toward their targets at several times the speed of sound.

That sharply reduces the time available to find and destroy a warhead.

When the warhead is hurled toward its target, “it’s very, very steep and it’s going at a ridiculous speed,” said Thomas Withington, an expert on electronic warfare at the Royal United Services Institute, who compared