Stars maintain the status quo and do not occupy land.

The occupation of galaxies and colonies by non-extinct regimes through war requires territorial claims, and the left column is yes, or the diplomatic page also has this option. After the armistice, you can choose to maintain the status quo and have occupied galaxies and colonies with territorial claims. Or choose to force the other side to surrender, you can have all the galaxies and colonies with territorial claims.

Find a few countries that are far away and can fight, and announce that the old enemies will increase their influence. If the influence comes up, the enclosure will be fast.