When US President Barack Obama hosts President Hu Jintao at the White House on Jan 19, it will be the 12th full summit meeting between American and Chinese presidents since former US president Richard Nixon made his historic visit to Beijing in 1972. A dozen summits in almost 40 years is testimony to the significance of each - and this - summit.

Of course, in today's world of diplomacy the importance of such summitry is somewhat diluted by the frequent meetings the two heads of state have at various international forums throughout the year. Presidents Obama and Hu have met seven times already and they speak regularly over the telephone, on average once a month. Personal and private communications are exchanged as well. All of this interaction reflects not only the institutionalization of US-China relationship, but also the changed nature of diplomacy in today's world.

Nonetheless, the role of a summit meeting (formal state visit) is special. It presents a unique opportunity for the two leaders to engage in truly comprehensive discussions about the totality of the relationship and the state of the world. When they meet on the sidelines of an international event, time and discussions are much more limited. The meeting in the White House on Wednesday, and the other interactions between President Hu's high-level delegation with their American counterparts, offers an important opportunity to bring some much-needed stability to the Sino-American relationship and to advance common cause where possible.

It is no secret that the US-China relationship has endured great difficulties over the past year since Obama paid a state visit to China in November 2009. It has been the worst year in Sino-American relations in at least a decade. Problems, many serious, have arisen in virtually every area of the relationship - diplomatic, economic, political, strategic, military, regional and global. Considerable distrust has grown on each side (both at the government and public level) in the process. The relationship cannot be said to be in either a healthy or cooperative phase - as disagreements, distrust and frustration have grown on each side.

Yet both governments have made real efforts over the past two months to improve the atmosphere before Hu's visit this week, and these efforts have helped to bring some new stability and sense of engagement with each other, while the summit itself offers the real opportunity to arrest the hemorrhaging of the past year. If the two leaders can find common ground on the grand strategic importance of the relationship in world affairs, and communicate this jointly and effectively, this will be a signal accomplishment. Hu will be warmly received and accorded an appropriately formal welcome befitting a state visit. So, the atmospherics will be conducive to reaching common strategic purpose.

The two leaders would do well not to get bogged down in discussing the long list of complex and contentious issues in the relationship. They need to focus on three broad categories of issues: global, regional, and bilateral - and choose one or two key issues in each category to focus on.

At the global level, this should be climate change and global economic recovery. At the regional level in Asia, it should be the Democratic People's Republic of Korea and Iran's nuclear program - and trying to integrate both into their regions following resolution of the nuclear issues of their respective nuclear programs. Bilaterally, the focus should be on liberalizing each country's investment climate for the other's companies, and narrowing China's trade surplus with the United States.

This is not to say that other issues - such as China's desire for the relaxation of US high-tech export controls or the US' concerns about human rights in China - are not important. They are. But priorities should be established for the summit dialogue.

The two presidents would also do well to establish some more institutionalized mechanisms to forge cooperation on a year-round basis. At present, the relationship is too episodic. It revolves around high-level meetings which occur a few times per year - while what is needed is the establishment of a series of intergovernmental working groups that work on a variety of issues together on a 365-day basis. China has this in its relationships with Russia and the European Union, and it would help the US-China relationship to bureaucratically move in this direction.

Despite the importance of these priority areas for discussion, the two presidents should elevate their discussion to recognize that they are the two most important leaders of the two most important countries with the two most important responsibilities in the world today. The US-China relationship is now a global relationship and needs to be addressed primarily on this level. The two presidents need to rise above the nitty-gritty details of contentious policy disputes, and grasp the "Big Picture" - the big strategic picture - and commit their governments to working together to address the major challenges to the planet and mankind today. The US and China are the two most important countries in the world - the world's No 1 and 2 economies, the two leading emitters of greenhouse gases, have two of the world's largest military budgets, and so on.

It is therefore incumbent on Presidents Hu and Obama to be global statesmen, and commit their countries and governments to common cause - where possible - to jointly addressing the many pressing issues on the global governance agenda today. The two countries cannot contribute to the betterment of the human condition and the world by pursuing their own narrow national interest. This is the opportunity that the summit in Washington really offers. The world waits to see what the outcome will be.

The author is a professor of international affairs and director of the China Policy Program at George Washington University in Washington, D.C.