While Beijing and Washington won't reconcile all their differences in two days, they might find some unexpected areas of convergence - Japan's rising nationalism fanned by right-wing political leaders has led to attempts to deny Tokyo's history of aggression and a bid change the pacifist constitution adopted under US supervision after World War II. China and the US also share a great many common interests and similar positions on issues ranging from the nuclear programs of the Democratic People's Republic of Korea and Iran to forging a mutually acceptable code of conduct for cyberspace.

A casual and relaxed summit at Sunnylands without much diploma-tic protocol offers a unique opportunity to catalyze the presidents' personal rapport. Though respective national interests will limit the extent of their exchange, they can start reassessing each other's intent by building up personal trust.

The two presidents have the opportunity to jointly open a window on relations between the two countries and breathe the air of freshly discovered trust.

There has been much talk about building a new type of great power relationship. The zero-sum US-Soviet Union relationship during the Cold War was typical of the traditional type of power relationship with mutual hedging and deterrence. In contrast to this, a new type of power relationship between China and the US ought to cultivate cooperation while not excluding healthy competitive interaction.

The two countries won't be able to avoid competition in almost all areas. But China still has a lot of catching up to do, especially in education, public health and innovation. Even if China is on a par with the US in terms of economic output in a decade, the gulfs between their per capita production and per capita incomes will still remain vast and nearly impossible to be ironed out within this century.

Hopefully the summit in California will build a consensus on respecting each other's core legitimate interests measured against international laws, so as to build an ordered and predictable bilateral relationship.

The author is professor and associate dean of Institute of International Studies, Fudan University.