The stakes in Asia’s maritime security tensions are high and getting higher. As each year the region moves closer to the global center of gravity in economic weight, military power and demographics, so too the consequences of any strategic breakdown among its powers become more grave.

Accordingly, it is more important than ever to work out what is going on. Yet there are confusing, contradictory narratives. Consider recent developments.

First, the good news. After years of frostiness and risk-fraught incidents at sea, China and Japan are back on speaking terms, just. President Xi Jinping and Prime Minister Shinzo Abe met briefly just before Monday’s Asia Pacific Economic Cooperation (APEC) summit in Beijing, in the first formal contact between the leaders of the two East Asian powers since 2012. The precise terms and conditions of this bonsai-proportioned rapprochement remain unclear, but broadly it seems that Japan has agreed to acknowledge that the two countries’ hold different views of the sovereignty of the Senkaku/Diaoyu Islands – a dispute by any other name.

More importantly from the point of view of regional peace and security, there are hints that long-suspended dialogue will resume towards developing operational channels of communication to prevent an encounter between Chinese and Japanese maritime forces from escalating into conflict. Whatever else has prompted this week’s mutual face-saving between Xi and Abe, it is fair to assume that somewhere within the Chinese system, the balance has finally begun to tilt away from risk-taking and towards risk-management as a policy touchstone on the handling of maritime issues.

There may be much to criticise about Abe’s reluctance to squarely face up to history – which his government is now signalling some willingness to do. But there is also much to commend about the disciplined way that Japan’s naval, airforce and coastguard personnel have face up to provocation for many months. History may show that the deterrent effect of this stance has helped shift the region from an unusually dangerous phase.

None of this leaves room for complacency. As President Obama flies east for a frenetic round of summitry – APEC closely followed by the East Asia Summit and the G20 – the locus of instability has moved from the East China Sea to the more complex differences of the South China Sea.

In both cases, historical animosities, nationalism, resource pressures and strategic imperatives are combining to generate tensions that can at best be managed, not resolved.

The newfound spirit of coexistence between China and Japan will have a downside if it allows Beijing now to concentrate coercive attention on one of its small Southeast Asian competitors for sovereignty in the South China Sea, whether the Philippines or Vietnam. Instead, the hope is that policy actors in China are beginning to realise that allowing or fostering tension in those waters, too, is in nobody’s interests.

An early test of whether the Chinese approach has comprehensively changed will come with the East Asia Summit (EAS), due to convene over the next few days in Myanmar. This is the most representative high-level forum in Indo-Pacific Asia, involving the leaders of the 10 ASEAN countries, plus China, Japan, South Korea, India, Australia, New Zealand, Russia and the United States.

The EAS is rightly mandated to consider region-wide strategic issues. By all means, the leaders should use this platform to focus on common concerns, like Ebola and the chilling rise of so-called Islamic State, better known as Daesh. And leaders, including President Obama, would be right also to endorse the progress in China-Japan relations. But the EAS cannot afford to be silent on the deepening trouble in the South China Sea, including China’s island-building and looming militarization of Johnson Reef and Fiery Cross Reef.

This means some real, live, unscripted exchanges of views on how to manage security tensions in the Indo-Pacific’s most critical sea lanes. China’s sincerity on negotiating a Code of Conduct ought to be tested with a call for a freeze on build new structures or changing land features in contested waters. And some signals need to be sent about the need for the EAS to evolve into more than just a meeting: it needs be affirmed as the keystone of regional security, with formal links to other promising institutions like the ASEAN Defense Ministers Meeting Plus, and a secretariat so that countries can put their crisis-management proposals and their concerns – including hard data about maritime security tensions – onto the record.

For President Obama to let this moment pass, or to assume that ASEAN partners do not want him to demonstrate principled leadership, would be a major diplomatic opportunity lost – conceding momentum and solidarity that he or his successor would then have to struggle to regain.

About Rory Medcalf

Rory Medcalf is Professor and Head of College, National Security College, at Australian National University and a Nonresident Fellow at the Lowy Institute for International Policy.