Domestically, we see megachange at work in the new attitudes and policies toward same-sex marriage, health care, smoking, and the widespread legalization of marijuana use. Globally, we have seen the extraordinary rise and then collapse of the Arab Spring, the emergence of religious zealotry, the growing influence of nonstate actors, the spread of ISIS-fomented terrorism, the rise of new economic and political powers in Asia, and the fracturing of once-stable international alliances.