A positive sign from the June no-necktie summit between Chinese President Xi Jinping and US President Barack Obama in Sunnylands, California, is the tone they set for building a new type of relationship between major powers, one that demands they work together to widen cooperation and narrow differences.

Although that proposal still calls for more content, you could almost hear and feel that message throughout the fifth round of the China-US Strategic and Economic Dialogue in Washington last week, when senior officials from both sides gathered to discuss a wide range of thorny issues.

It was in sharp contrast to the rhetoric last year when Republican presidential candidate Mitt Romney made a number of "Day One" vows about getting tough with China - Obama following suit with some harsh words of his own.

It was also in sharp contrast to the buildup to the Sunnylands summit when the only words about China in the United States were allegations of Chinese cyberattacks.

The National Security Agency contractor Edward Snowden's revelations changed that: Those noisy folks that accused China of hacking US computers have kept relatively quiet lately. Yet this does not mean that the two sides have become closer on the issue.

The US has tried to play down Snowden's disclosures, arguing that it is what every government does. However, many countries, including its allies, are furious at the excessive US spying. China, which has been a victim of repeated cyberattacks, believes that international norms on cybersecurity should be worked out through the United Nations.

No one knows when the two will reach a consensus on the issue, but the good thing is, both have agreed to discuss the issue through the newly launched working group on cybersecurity.

Another newly established group - the joint working group on climate change - actually achieved concrete results, with the world's two largest economies and two largest greenhouse gas emitters announcing five initiatives to cut emissions and reduce air pollution.

The S&ED last week identified 91 areas for further cooperation in strategic areas and both countries promised more economic, trade and investment cooperation. Both seem excited about the prospect of starting formal talks on a bilateral investment treaty.

However, differences remain, for example over the territorial disputes in the South and East China Seas, the US' restrictive policies on high-tech exports to China and the US rebalancing to Asia strategy.

Given their huge differences in political, cultural, historical and social backgrounds, the two nations will possibly have to live with some of their differences for a long time to come.

Some people have criticized the Sunnylands summit for failing to produce concrete deliverables, except the agreement on phasing out hydrofluorocarbons, potent greenhouse gases.

My feeling is that the most important success at Sunnylands was indeed the tone struck and the consensus that both sides should work together to avoid the catastrophic historical norm of conflict between a rising power and an existing power. It certainly established a clear direction for the two countries to follow.

As the co-chairs of the S&ED for the first time, Vice-Premier Wang Yang, State Councilor Yang Jiechi, and Secretary of State John Kerry and Secretary of the Treasury Jack Lew got to know each other better, paving the way for a better future working relationship. The same is true for the dozens of cabinet officials and ministers from the two governments, many of whom also met for the first time.

US officials have already praised Wang for his sense of humor. And that was a good beginning.

The four co-chairs often described their talks as a "candid discussion", which, compared to the shouting games and lecturing we have seen so often in the past, shows the relationship is maturing.

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

(China Daily USA 07/19/2013 page15)