Imperial Rift

Defection. Once it starts, the flood gates open as Imperial troops sent to the Frontier to die for the Emperor suddenly see a chance to survive by hopping across the border into the Green Empire. The mass civilian exodus was bad enough, but when the Emperor's own fleet starts doing so in alarming numbers only a bit of trickery on the part of the Emperor is going to lead to victory before he loses too many ships to the growing sanctuary of sanity that is the Green Empire.