Many readers know the lines from the 19th century fable about Goldilocks and the three bears: 'not too hot, not too cold, just right.' Those lines come to mind when reading the mostly positive initial reports of the informal summit between presidents Obama and Xi. These two leaders needed to get it 'just right' if this summit and the opportunity for the two to get to know each other are to have any substantive effect on US-China relations.

Now and in the future, Obama needs to ensure that he is not perceived as having conceded too much to China. Xi must ensure that he is perceived as having gotten enough for China. It's a fine line to walk if both are to be viewed as winners.

Economic interdependence between the two countries is deep, and both acknowledge the need to cooperate with each other. Yet the fundamental strategic goals of Beijing and Washington are at odds. The US is the world's only superpower and wishes to preserve its dominant position. Beijing, the rising power, wants control over what it sees as its core interests in its periphery, especially the East China Sea and South China Sea.

Will a personal connection between Obama and Xi make a difference? It won't remove the tension in the two countries' strategic intent. But it could help iron out misunderstandings and contribute to problem-solving on pressing issues of mutual interest, like North Korea.

But it would be unrealistic to expect too much from one summit. Both leaders, especially Xi, are constrained by pressures from elites back home which have very diverse views of how to deal with the other.

China would like to see the 'new kind of great power relationship' (the term Xi promotes to describe China-US relations) as being one between equals. Some Chinese commentators already insinuate that the summit did indeed cement that definition.

From Washington's viewpoint, this is not getting it 'just right'. The US remains the dominant, established power, while China is the rising power. Tensions between Washington and Beijing are bound to continue, whether or not Obama and Xi get along at the personal level.