The world seems a more dangerous place in the five years since the attacks of September 11, 2001, given the quagmire of Iraq, war in the Middle East and ongoing terrorist plots. Yet through the gloom come signs across East Asia that September 11 has acted as a catalyst for broader co-operation and engagement that was previously thought inconceivable - led by better intelligence and law-enforcement.
Intelligence officials, scholars and diplomats talk of converging security interests stripping away perennial suspicions between the region's nations and towards the US. Some also express hopes of co-operation expanding beyond terrorism into the wider security arena.
From the US relationships with Beijing and Hanoi to the traditionally awkward troika of Indonesia, Singapore and Malaysia or the tense border between Thailand and Cambodia, working-level ties are expanding in the fight against terrorism, despite wider political concerns about the Bush administration's foreign policy and its Iraq adventure.
'It has been a long road, but it is really quite remarkable to think of the progress that has been made across the region,' said John Harrison, of the Institute of Defence and Strategic Studies, in Singapore. 'The sort of co-operation we are now seeing represents something of a victory in itself, even if it is by its nature secretive and hard to quantify. Co-operation is the only way we are going to defeat a globalised network ... we are seeing a recognition now that it is not just a US issue, that most nations are potential targets, whether they are a westernised, industrialised or developing nation.'
For some, Indonesia serves as a metaphor for the wider progress. In the months after September 11, US intelligence officials grew alarmed at a lack of recognition within the world's largest Muslim nation of the threat posed by internal terrorist networks, specifically the so-called Jemaah Islamiah.
Then-president Megawati Sukarnoputri struggled to deal with domestic Muslim politics. Internal pressures grew after her long-planned visit to Washington within a week of the September 11 attacks.
Some Indonesian officials told foreign counterparts that they believed terrorism was far down a list of priorities for a newly democratic archipelago fighting corruption, decades of poor governance and poverty, as well as independence questions over East Timor and Aceh. Issues of sovereignty and interference in internal affairs were inevitably invoked as foreign envoys tried to press the issue.
The alarm intensified as the first anniversary of the World Trade Centre attacks approached. Foreign diplomats struggled to force action over Jemaah Islamiah.
'We were just pulling our hair out at that point,' said one US law-enforcement official involved at the time. 'I've never known tension like it.' Within a month, on October 12, 2002, bombs ripped through packed nightclubs in Kuta on the popular tourist island of Bali. Some 202 people - Australians, Indonesians, Americans and Europeans - were killed, including 11 people from Hong Kong. A further 209 were injured. The the JW Marriott hotel in Jakarta was bombed in 2003, a crime for which extremist Muhammad Rais jailed for seven years. Then there was the Australian embassy blast in 2004 and the suicide bombings in Bali last October. The 2002 Kuta bombings led to a sea change in terms of intelligence-sharing and co-operation.
Australian offers of on-the-ground law-enforcement and intelligence assistance were taken up by Indonesian officials almost immediately - an act unprecedented given the nations' thorny political and cultural divides.
Jemaah Islamiah's spiritual head, the cleric Abu Bakar Bashir, was among those arrested. After extensive legal manoeuvrings amid intense international pressure, he was eventually found guilty of conspiracy over the Bali attacks. Sentenced to 21/2 years, he was released earlier this year after serving less than 26 months, despite concerns voiced by the US and Australia.
The working relationship, at times still sensitive, has broadened and deepened under the watch of current Indonesian President Susilo Bambang Yudhoyono, according to diplomatic sources on both sides. It has helped foster closer ties with regional counterparts and the US. Australian counter-terrorism officials are now based in Jakarta to train Indonesian counterparts.
'Indonesia is committed to this fight, the world has come to understand that,' one Indonesian diplomat said. 'Although there may be public differences in approach, make no mistake, behind-the-scenes efforts to share intelligence have never been greater.'
One former Pentagon and State Department official involved in the region at the time said he now believed the regional fight against terrorism was intensifying in terms of 'capability, co-operation and desire'.
'You can now see a situation developing where countries know it is in their interest to co-operate on a deep and close working level to tackle terrorism,' the former official said.
'At first, some nations, if they were taking any action against terrorists at all, were doing so largely because we asked them to, not because they saw it as really in their own interests. That is no longer the case ... all nations realise that this problem also affects them, it is in their interest, so their co-operation and efforts are sustainable.'
Insiders also point to the recent return of terrorist suspects from Indonesia to Singapore as a sign of wider progress that would also have been difficult to imagine previously. A formal extradition treaty is expected to move through the Indonesian parliament soon. The co-operation has flowed into related areas, too. Last year, Indonesia, Singapore and Malaysia started joint patrols of the Malacca Strait - the pirate-plagued shipping lanes through which much of the region's trade passes. Joint patrols had long been mooted to protect shipping, but were generally considered stuck in the too-hard basket, given long-standing sensibilities and frictions.
Closer working relationships have eased old suspicions, however.
'It is hard to imagine those joint patrols taking place before,' said Derek Mitchell, a senior fellow at the Centre for Strategic and International Studies in Washington. 'The closer working relationships forged by the fight against terrorism appear to be paying off in other areas.'
The relationships are backed by more long-term efforts in the Association of Southeast Asian Nations. Over the past 18 months, regular meetings of defence ministers, interior ministers and police forces have become the norm - areas once quietly ignored by the organisation in favour of less sensitive areas of co-operation.
It is a pattern noted elsewhere in the region. On the mainland, western intelligence agencies have forged unprecedented relationships with counterparts as the practical demands of the fight against terrorism hit home. US officials had been working for much of the 1990s for Beijing's approval to set up a liaison office of the Federal Bureau of Investigation - America's main domestic anti-terror organisation. After several false starts, approval was granted within a year of the September 11 attacks. The office was formally established two years ago.
The State Department's latest anti-terrorism report noted the mainland's co-operation in fighting money laundering, its intelligence-sharing and container-security projects in ports in Shenzhen and Shanghai.
'Chinese law-enforcement responsiveness to terrorism-investigation requests still needs improvement, but substantive intelligence has been obtained in some cases,' the report stated. 'The Ministry of Foreign Affairs described US-Chinese co-operation on counterterrorism as a key partnership promoting international stability and as a pillar of the bilateral relationship.'
Arguably the most intriguing - and potentially controversial - spin-offs are the recent changes to Japan's military footing. Five decades of pacifism - enshrined in Japan's post-war constitution - are changing.
A recent agreement with the US, its major military ally, will see Japan take a much more active role in their security alliance at a working level. Changes to the constitution allowing far greater involvement in foreign conflicts are now considered a political fait accompli over the next one or two years.
The moves follow the involvement of Japanese forces and ships in military operations in Iraq and against Afghanistan - a far cry from the cheque-book approach Japan took to its support in the 1991 Gulf war. The former Pentagon and State Department official said he was in no doubt that September 11 had fed into the drive to transform the alliance.
'Things happened over weeks and months that would have taken years,' he said. 'It was amazing to see how comfortable Japanese officials and the public were talking [of] Japan's self-defence forces in terms of their regional and global role. Previously, their reaction to contributing to a coalition would have been cheque-book diplomacy ... there was a realisation in Japan that they had to move beyond that and get directly involved.'
The rise of Japan's military is one factor challenging the strategic assumptions that have governed Northeast Asia for decades - and one being scrutinised across the region, irrespective of the 'war on terrorism'. Even as military, intelligence and law-enforcement relationships improve on the ground, other regional rivalries could put them at risk.
How has the world changed in the five years since the September 11 attacks? Don't miss the SCMP's week-long series of reports, beginning on Tuesday