To me it seems clear that a way of uniting all of the powers has to be found.
But by that, it might be perceived that all of the resources and investment that has gone into armaments might have been wasted.
What is needed, it seems to me, is maybe a new common external enemy, to focus on.
Whether that enemy is fictional or not doesn’t matter, it would do no harm to believe that there is a hostile force "Out there", planning to do horrible things to us, thus who we should unite against as a species, and get tooled up to defend ourselves against.
I wonder if anything might just come to be known about that :)