ASIA'S security has declined since the last Shangri-La Dialogue in Singapore, where the focus of Vietnamese Prime Minister Nguyen Tan Dung's opening speech was the strategic trust deficit in the region. Referring to the South China Sea, he warned how single irresponsible actions could lead to the interruption of trade flows, ultimately damaging the global economy. He quoted a Vietnamese saying: "If trust is lost, all is lost."
One year on, these words are particularly ironic in the wake of the dramatic escalation between Vietnam and China triggered by the arrival of a Chinese oil rig in the disputed waters of the South China Sea.
A wave of lethal anti-Chinese sentiment has spread through Vietnam. Prime Minister Dung is threatening to take defensive measures, including legal action against China. Miscalculation, it seems, remains a major danger for big and small powers alike.
The 13th International Institute for Strategic Studies Shangri-La Dialogue convenes in Singapore over this weekend amid mounting uncertainty over the security of the Asia-Pacific region and the ability of regional powers to curb this downward spiral.
Tensions are running high on the Korean peninsula, where North Korea is reportedly making preparations for a new nuclear test. Friction between China and Japan in the East China Sea spiked six months ago and now confrontation in the South China Sea has once again returned to the headlines.
During preparatory discussions held in Singapore in January, Minister for Defence Ng Eng Hen pointed out that nationalist ambitions, progressive military modernisation and dynamic changes in power relations form the backdrop to recent events in Asia.
Recent changes to Japan's national security strategy, for instance, are an acknowledgement that in recent years the security environment around Japan has changed dramatically.
Japanese Prime Minister Shinzo Abe's keynote address tonight at the Shangri-La Dialogue will be studied by leaders, policymakers and commentators seeking an understanding of tectonic shifts in geopolitics and how the security environment will be affected.
Mr Abe may seek to articulate his plans for a more muscular defence policy, supported by new Japanese legislation enabling Japan to contribute more to international security. Mr Abe may also elaborate on why he is pursuing changes to Japan's Constitution to allow "collective self-defence" - essentially the right to use force in defence of an ally (the United States) under attack.
Mr Abe's national security overhaul has generated deep suspicion in China, aggravated by having top leaders in Japan continuing to visit the Yasukuni Shrine where some of Japan's most infamous war criminals are interred.
At the heart of the matter, however, are the enduring Japan-US alliance, the military element of the US rebalancing policy to Asia, and China's growing military clout.
Chinese President Xi Jinping, on the other hand, has developed his own vision for the security of Asia, incorporated into the "China Dream".
Earlier this month in Shanghai, at the Conference on Interaction and Confidence Building Measures in Asia, Mr Xi scorned "Cold War thinking" and "zero-sum game" mentality. Calling for a new regional security architecture, Mr Xi stated that: "A military alliance which is targeted at a third party is not conducive to common regional security." Notably he called for security problems in Asia to be solved by Asians through cooperation. China's participation at the Shangri-La Dialogue will inevitably reflect this vision.
US President Barack Obama last month concluded a week-long four-country tour of Asia in an effort to buttress the US rebalance to Asia. He did not visit China. At the close of his trip in the Philippines, Mr Obama emphasised iron-clad resolve to resist "external aggression" and threats to freedom of navigation.
China's template for regional security is effectively one stripped of America's involvement, encompassed in Mr Xi's latest dictum: "Asian solutions to Asian problems."
The view of many regional states, however, is the complete opposite. It is one that envisages the United States continuing its long-held role as a guarantor of security in Asia in the absence of any credibly promising indigenous alternatives, such as Asean+3 for example.
The underlying concern of this year's dialogue will be mounting dissatisfaction at the inadequacy of regional mechanisms to address increasingly palpable threats to regional security. All five plenary sessions have been designed to encourage discussion of strategic restraint, to foster greater cooperation among the armed forces of the region and to promote better awareness of the management of escalation.
This year's Shangri-La Dialogue will therefore serve as a litmus test in assessing the capacity of Asia-Pacific players to halt the deterioration of regional security that we have witnessed over the last 12 months.
The writer is Shangri-La Dialogue Senior Fellow for Asia Pacific Security at the International Institute for Strategic Studies-Asia (IISS-Asia) in Singapore. The IISS organises the Shangri-La Dialogue which opens today.