IX.10 On the weakness of neighboring states
When your neighbor is a state in decline, it would be a mistake to hasten its ruin, because you are in this respect in the most fortunate situation that can be hoped for, there being nothing so convenient for a prince as neighboring another who absorbs for him all the blows and calamities of fortune. And it is rare that by conquering such a state your real power is increased as much as you have lost in relative power.