Chinese President Xi Jinping (L) and Ray Conner (R), president and CEO of Boeing Commercial Airplanes, tour the Boeing assembly line in Everett, Washington September 23, 2015. [Photo/Agencies]

The past few years have seen a positive trend in China-US military relations. This was made possible because the two countries realized that peace and cooperation are essential to not only Chinese and American citizens, but also people in the rest of the world.

China, despite becoming the world's second-largest economy and growing in national strength, has stuck to its peaceful development strategy. It will neither challenge the US' dominance nor form alliances with other countries. And even though some of its neighbors seek to create trouble over maritime disputes, it insists on a defensive defense policy and advocates a political, instead of military, solution to the disputes.

China's idea of a "new model of major-country relationship" also makes it clear that it has no intention of confronting the US, which also helps keep their differences on security issues under control and draws the bottom line of military relations.

In particular, on non-traditional security issues such as overcoming the economic crisis, preventing environment pollution, combating cross-border crimes and terrorism, and nuclear non-proliferation, the two sides are more willing to cooperate, which helps cultivate a new model of bilateral military relationship.

The two countries' ever-deepening interdependence also plays a big role in maintaining a balance in bilateral ties. China is the third-biggest market and second-largest trade partner of, and the biggest exporter to the US. And in 2014, more than 270,000 Chinese students were studying in the US. All this makes it hard to imagine a global order without China-US coordination.

Yet there are obstacles that prevent bilateral military relations from developing further, with the difference in ideology being the strongest. Their different social systems make it difficult for the two countries to reach a common understanding on contentious issues.

They differ on some practical policies, too. For example, the US, to implement its "pivot to Asia" policy, has been strengthening its military presence around China and has held several joint military drills with China's neighbors. US military aircraft and vessels have been found spying on China a number of times over the past years, which could have easily caused misunderstandings. Such policies and actions are not conducive to improving bilateral military relations.

In disputes that do not conflict with its core interests, the US appears as a third party taking sides rather than staying neutral. On China's territorial disputes with Japan over the Diaoyu Islands in the East China Sea and the Philippines in the South China Sea, Washington stands with Tokyo and Manila even though all historical evidence show the disputed islands and reefs are Chinese territory. Besides, US politicians speak in a language that suggests China would restrict free navigation in the disputed waters once it regains control over them, because they choose to ignore Beijing's repeated vows to guarantee free navigation.

Differences also exist in areas of traditional security such as those concerning territory, sovereignty and military capability. Among them the most important is about Taiwan, which the US accepts is indisputable Chinese territory but still intervenes in to mar the possibility of unification. That's a big bottleneck in Sino-US military ties because it concerns China's core interests: territorial integrity and sovereignty.

Although China has been reiterating that it will never seek hegemony, not be the first to use nuclear weapons and never use nuclear arms against non-nuclear states, the US refuses to trust it. Instead, it describes China as a potential strategic competitor.

Moreover, the US expects China to support its unilateral actions while China expects the US not to intervene in its internal affairs. They have remained expectations. It is thus clear that lack of mutual trust is still preventing bilateral military relations from developing smoothly.

So one could conclude that differences and cooperation will co-exist in Sino-US relations. Common interests outweigh differences, though.

Despite the tit-for-tat between the two sides, US leaders have repeatedly said they welcome a rising China, while Chinese leaders have said more than once that the Pacific is big enough to accommodate both countries. As such, decision-makers on both sides need to remember that a strong military is vital to the healthy development of overall bilateral relations.

The author is deputy general secretary, China Arms Control and Disarmament Association.