We think of military alliances, traditionally. But the truth is that international cooperation in those listed categories is quite strong in places.
98. Since relationships between States must be regulated in accordance with the principles of truth and justice, States must further these relationships by taking positive steps to pool their material and spiritual resources. In many cases this can be achieved by all kinds of mutual collaboration; and this is already happening in our own day in the economic, social, political, educational, health and athletic spheres—and with beneficial results. We must bear in mind that of its very nature civil authority exists, not to confine (people) within the frontiers of their own nations, but primarily to protect the common good of the State, which certainly cannot be divorced from the common good of the entire human family.
99. Thus, in pursuing their own interests, civil societies, far from causing injury to others, must join plans and forces whenever the efforts of particular States cannot achieve the desired goal. But in doing so great care must be taken. What is beneficial to some States may prove detrimental rather than advantageous to others.
As long as the common good applies across international borders, this will be a fruitful endeavor. Missteps will happen. But a focus on cooperation, especially non-competitive cooperation (I think of the arts–not mentioned here, but potentially more fruitful than athletics) may be important to explore.