The two-day set of meetings between Mr Obama and Mr Xi this weekend in Southern California is unprecedented.
First, it's unprecedented that a newly minted Chinese leader would head to the US this quickly. Second, the meeting will avoid the usual pomp and ceremony of a state visit, as well as the short, highly scripted exchanges that have marked previous meetings.
This is all to the good, given the long list of issues the two presidents need to discuss. Indeed, two days is just sufficient to talk about them, not resolve them.
Not surprisingly then, on background, both the Chinese and American side have emphasised that the meeting's real goal is to start building a personal relationship between the two leaders in the hope that it will create momentum for addressing problems of US-China relations in the future.
But rarely does statecraft work this way, especially when the disputes between the two countries are not ones of misunderstanding but are, instead, rooted in fundamental differences in history, political systems, and the norms that should guide the international system.
The danger is not that, after two days, the two presidents will not get along personally. The real danger is that, in an effort to get along, they will be less than frank with each other about the actual sources of the problems in the relationship.
That's a recipe for greater, not lesser, problems down the road.
Gary Schmitt is director of the Marilyn Ware Center for Security Studies at the American Enterprise Institute.