Scanning the regional landscape today, South-east Asian states ought to be quite optimistic about the state of Asean-China relations just as the year closes on the 25th anniversary of the establishment of their dialogue partnership.

Asean and China have agreed to a series of confidence-building measures to lower the temperature on the South China Sea issue. The Philippines, after years of sabre-rattling with China, now appears to be embracing Beijing just as Manila is about to take up the Asean chairmanship. And a range of Chinese-led economic initiatives that benefit the region are being rolled out. The prospects for "win-win cooperation", as the Chinese like to term it, seem to be quite bright.

Yet speaking to some other South-east Asian participants in Beijing for the seventh Xiangshan Forum last month, this was far from the case. Several of them conveyed the same feeling one gets travelling around South-east Asian capitals today: a palpable uncertainty about China's rising capabilities, dubiousness about its true intent, and fear as to how Beijing may misinterpret major shifts - including Manila's apparent pivot - as indicating the wisdom of its current course rather than its follies. South-east Asian countries may be gaining to varying degrees, but they certainly do not feel like they are winning.

The lingering uncertainty about China in the region reflects many things, but one of them is the structural limits of the Chinese concept of win-win cooperation. Win-win emphasises mutuality but ignores several other dynamics at play in the Asean-China relationship today from a South-east Asian perspective, including the vast and rising asymmetry in capabilities between China and Asean states; the uncertainty about Beijing's long-term intentions; and the reality that there are often both winners and losers within the countries that engage with Beijing.

If South-east Asian states do not see themselves as winning the way China does, that should worry Beijing. The true test of whether a major power is succeeding at being a good neighbour lies in not what it thinks about itself, but what smaller states perceive. Discontent among Asean countries also undermines China's strategic goals, since they will be less willing to embrace Beijing and more likely to diversify their relationships away from it.

What, then, can China do? One option is to go beyond mutuality and move towards magnanimity, sacrificing short-term self-interest for long-term goodwill. Call it lose-win diplomacy.

A Filipino fisherman fixing nets next to a fishing fleet at Masinloc port in Zambales province. Beijing should not only demonstrate its generosity on bilateral issues such as access to Scarborough Shoal, but use this as an opening for bolder measures too. PHOTO: AGENCE FRANCE-PRESSE

Part of lose-win diplomacy is demonstrating to Asean states that China can compromise even on traditionally difficult issues. The South China Sea is the most obvious candidate, and the Sino-Philippine front is the immediate test.

Manila has already bent over backwards in its effort to repair ties with China. Instead of just trying to eke out the best deal or remaining cautious, Beijing should use this opportunity to demonstrate its generosity on difficult issues including the South China Sea.

This means not only being generous on the bilateral front on issues such as access to Scarborough Shoal, but using this as an opening for bolder measures too. With it being Asean's 50th anniversary next year, there are few better ways for China to support community-building than to actually help ensure the conclusion of a meaningful code of conduct on the South China Sea in 2017, a sharp break from its foot-dragging in the past.

And maybe after the dust settles a little more, Beijing could also start bringing its nine-dash line (which is now legally invalid) into line with international law. Greater clarity on such issues could help remove potential roadblocks to the realisation of its economic initiatives like One Belt, One Road.

Lose-win diplomacy is not just about how China handles issues that are difficult for it, but also how Beijing reacts when the going gets tough for others.

Moments of crisis do a lot to either promote or undermine trust, and the reactions of major powers can also help amass goodwill and demonstrate their role as responsible actors.

China has not hesitated to help its closest friends when they are in trouble. Beijing's much-needed purchase of Cambodian rice earlier this year to help save its rice sector was a case in point. In such cases, Beijing is seen as strategically bailing out key states in order to further its interests, including managing the fallout from its assertiveness in the South China Sea.

Where China has found things more difficult is when it has had to sacrifice its short-term political interests. Irrespective of what its motivations were, China's paltry aid donation to the Philippines after Typhoon Haiyan in 2013 - initially at just US$100,000 - was embarrassing as it showed it was unwilling to set aside ongoing disputes to help a country in need.

Similarly, China's fierce criticism of Malaysia's handling of the missing Beijing-bound Malaysian Airlines flight MH370 in 2013 was seen as an example of how Beijing had chosen to pander to nationalist sentiments at home rather than helping a friend in distress.

If China wants to amass the goodwill necessary to cultivate its image as a responsible major power and to get more support for regional initiatives it is leading, it needs to be less petty and more forgiving and empathetic when other countries have it tough.

Even more significant would be Chinese efforts to aid countries in the event of natural disasters in concert with the US alliance and partnership network in the Asia-Pacific which it so often rails against. If there is any area where there is the potential for such collaboration to start between Beijing and Washington, surely it is this one.

Promoting lose-win cooperation requires respect not just in Beijing's relationships with South-east Asian states, but these states' alignments with other actors as well.

China's recent criticism of Singapore has been rather unfortunate in this regard. Not only does this cast doubt on China's willingness to respect the autonomy of South-east Asian states, it reinforces these states' uncertainty about Beijing's rise, which in turn further feeds into their desire to diversify their relationships away from China.

This respect should apply not just to South-east Asian countries wanting to diversify their alignments, but other powers in the Asia-Pacific and beyond that want to strengthen relationships with Asean states as well.

If China can react to proposals from others, whether it be the Trans-Pacific Partnership from the United States or the New Southbound Policy from Taiwan, in the spirit of healthy, positive-sum cooperation instead of initial, zero-sum suspicion, it will seem more like a confident rather than insecure power.

To be sure, there are limits and risks to undertaking lose-win cooperation. China has its own constraints, and it cannot be seen to just be signing off on generous deals that are bad for its companies, or giving up sovereignty that could undermine the legitimacy of the government.

And, of course, the degree to which Beijing is able to do all this is contingent upon how regional states react, and how other powers including the US respond. Washington, too, is no stranger to adopting zero-sum thinking, with its initial position on the Asian Infrastructure Investment Bank being a case in point.

But rather than pointing fingers and dragging its feet, Beijing should set the standard for a region it wants to define. That would constitute true leadership.

• The writer is associate editor of The Diplomat magazine based in Washington, DC and a doctoral candidate at the Fletcher School of Law and Diplomacy at Tufts University researching on Asian security issues and US foreign policy in the Asia-Pacific.