[JumpCrisscross]

> LEO is the exact place you need to be careful. Higher orbits have more space and have fewer satellites overall so it's less of a concern

No. In LEO orbits degrade in single-digit years at most. There is no known solution for rendering an orbit in LEO inaccessible with a Kessler cascade—the best you can do is blind an area with repeated ASAT fire.

In higher orbits debris last longer. That makes cascades possible, though again it only denies a limited area and requires almost active effort.