President Donald Trump’s visit to China in mid-May was filled with carefully choreographed photo ops, diplomatic pageantry, and announcements of blockbuster commercial deals. The deeper significance of the summit, however, is that Washington and Beijing are beginning to accept that neither side can force the other into submission. After years of trade wars, technology controls, and military competition, the two countries are discovering the limits of coercion. This does not mean the two superpowers will reconcile or that they will turn back the clock to policies based on engagement. It means the beginning of a new G-2 world—a world in which the United States and China can restrict, punish, and disrupt each other, but they cannot dominate or exclude each other. The United States remains the world’s military powerhouse, but China can now push back on Washington’s power projection in the western Pacific.…