The same is true on the issue of cybersecurity. It is probably hard to convince anyone that the US is more threatened by cyberattacks than anyone else, especially since it runs the world's most powerful surveillance facility, the National Security Agency. So any talk of setting international norms in cyberspace should start with US setting a good example.

The South China Sea is likely to be a hot issue. But instead of trying to force its "freeze" solution upon others, the US should have faith in the wisdom of the countries directly involved and their ability to solve the issue peacefully.

It would be naive for anyone to think any of these complicated historical issues can be fixed overnight. A reminder is that after pursuing regime change and spreading so-called freedom and democracy in the Middle East for more than a decade, the US is faced with the nightmarish rise of the Islamic State group armed with US weapons.

Obama and Xi should not be obsessed with one single issue. Yet, the tone they set will be enormously important for their subordinates to follow in the coming years, whether in the trade or military field.

The informal summit in Sunnylands, California, in June last year, drew global attention and made many people excited because both leaders pledged to expand their cooperation and effectively manage their differences. But despite the ensuing growth in military-to-military exchanges and expanding trade and people-to-people ties, we have seen the intertwined relationship being easily hijacked by negative rhetoric over the differences and by one incident after another.

That makes it all the more important for the top leaders of the two countries to meet more often and put more emphasis on expanding cooperation. After all, cooperation has been the main theme of China-US relations over the last four decades.

The author, based in Washington, is deputy editor of China Daily USA. E-mail: chenweihua@chinadailyusa.com