The big question is how effectively he can apply his accumulated soft power to make a difference on the world stage. [...] But the pope's most audacious foreign-policy move has been a crusade against worldwide income inequality and environmental degradation, including man-made climate change.

How will the social science experiment of allowing wealth to settle so unequally between the top 1 percent and rest of the United States impact the foundations and contours of U.S. foreign policy?