The fact that Chinese Vice President Xi Jinping’s visit to Washington has been overshadowed by the frenzy over Iran is an indictment of the Beltway foreign-policy establishment’s priorities. The U.S.-China relationship is far more consequential than Iran, the Israel/Palestine dispute, the war in Afghanistan, or any other development in southwest or central Asia. This relationship will define U.S. foreign policy in the 21st century.

During the trip, Xi is likely to highlight the cooperative aspects of the U.S.-China relationship such as trade and the two countries’ shared interest in shoring up the global economy. The leaders are likely to gloss over their differences on issues such as intellectual property, the value of the renminbi, and creeping protectionism. Further down the list of issues are the growing security disputes between China and U.S. partners in the Asia-Pacific: the status of China’s claims in the South China Sea, the growing U.S. military presence in China’s region, and Beijing’s belief that Washington is encircling China militarily. It should be expected that these more contentious issues will take a backseat in the discussions, at least in public.

But putting the relationship on a sounder footing requires addressing security issues. Power transitions have represented some of the most unstable periods in world history. Should China’s relative power continue to grow, its ambition is likely to do the same. Given that there are few signs that Washington will welcome a larger Chinese role in Asian security issues, this could portend serious disagreements in the years to come.