ladder-north
The strike pattern used to hit targets with nuclear weapons from over the north pole. Such a strike would hit the southernmost targets first, moving from east to west, then hit the next series of targets to the north from west to east. From overhead the hits would appear to make the rungs of a ladder, giving rise to the name. This kind of strike is used with nuclear munitions to prevent warhead fratricide.
The SIOP calls for a ladder-north against their southern defenses.