Stalemate

While Imperial forces failed to destroy the insurgency, they at least managed to thwart the Rebels' attempt to overthrow the …. With this peace treaty, all of the rebelling members of the Galactic Imperium have been granted independence. Perhaps it is for the best. A disease such as this must be cut out before the corruption has a chance to spread. We can always rebuild and return these wayward systems to the bosom of the Imperium at a later date...

The command below will trigger the "Stalemate" event in Stellaris:

When this event fires, you can choose between the following option:

• The Imperium shall endure.