It has become common to charge one’s political opponents with “doing what ISIS wants”. This is based on the idea that one should always act against the ambitions of an enemy. Here are two reasons to doubt this…
- An enemy’s ambitions are not all that oppose one’s interests. If an enemy poses an immediate existential threat to one’s state its defeat becomes all-important but in a world of numerous competing interests, and numerous different dangers, it can be wise to do X even if it strengthens an opponent because the good consequences outweigh the bad.
- An enemy’s ambitions might contradict its interests. One should not assume that one’s enemies are so intelligent that doing what they want is the same as doing what they should. (Germany declaring war on Russia comes to mind.) The phrase “give ’em enough rope” was invented for a reason.
Acting against the ambitions of opponents is always secondary to acting in the interests of oneself.