This can be summarized in the old adage, (roughly) "There is nothing that binds people together like a common enemy". I don't see anything ground breaking here.

This can be summarized in the old adage, (roughly) "There is nothing that binds people together like a common enemy". I don't see anything ground breaking here. External conflict can cause internal unification. Of course, to elicit cooperation, there needs to be a common benefit or good to all parties involved. But external conflict is not the only possible stimulus, though it might be the easiest to trigger.