>some experts say
NBCNews
hmmm so that would be whoever was standing around the water cooler in the NBC office then.
Cruise missiles generally operate at high speed and low altitude.
This is what makes them difficult to shoot down.
By flying at low altitude defenses have little time to detect and react to the threat.
Their more modern smaller cousins are the shorter range attack/suicide drones.
These attack/suicide drones do use turboprop and piston engines and generally operate at lower speeds and shorter ranges.