"In the Global Age, we must be prepared to engage in regional conflicts selectively — where the stability of a region important to our national security is at stake; where we can assure ourselves that nothing short of military engagement can secure our national interest; where we are certain that the use of military force can succeed in doing so; where we have allies willing to help share the burden, and where the cost is proportionate. America cannot be the world's policeman. But we must reject the new isolationism that says: don't help anywhere, because we can not help everywhere."