"At the beginning of the year 2001, no one could predict or imagine what was coming with the 9/11 attacks and everything that followed. American intelligence got some information, but no one really trusted that information.
"We could be in the same situation right now. Who can say what will happen after Syria? I fear we are in a pre-9/11 situation."
This is a devastating wake-up call because it comes from a man, let's call him Ali, who is one of the most senior figures associated with Indonesia's security policies.
I met him a couple of weeks ago, early one evening, in the acrid, smoke-filled cigar bar of one of Jakarta's five-star hotels. His judgment, which he supports with dense data and close reasoning, is informed by decades of critical experience. It is a judgment made long before a Malaysia Airlines flight disappeared over the South China Sea on Saturday, in an incident which may or may not be terrorism.
Ali asked that I not use his name. His dire judgment is shared by another key Asian intelligence figure. Ajit Doval is a former director of the Indian government's Intelligence Bureau. He has spent a lifetime in counter-terrorism. If the opposition Bharatiya Janata Party wins India's forthcoming election, as is widely expected, Doval is favoured to become national security adviser.
I don't know if Ali and Doval have ever met.
Here is Doval's net assessment. It is eerily similar to Ali's: "We have to brace ourselves for living in a world which is much more insecure than it was in 2001."
Talking to both Ali and Doval gives a kind of stereoscopic depth of view to the re-emerging terror threat. They share key concerns: what is happening in Syria, what will soon happen in Afghanistan, the growing popularity of al-Qa'ida ideology in North Africa and the Middle East and the deep strategic planning of jihadist networks.
Let's start with Ali: "We are very worried because of this latest situation in Syria. Not only that there might be another 9/11 or Bali bombing, but the contribution it's making to the progress of radical jihad thinking.
"Our analysis is that Syria is more dangerous than Afghanistan was (as a training ground) because they've got much more head-to-head battle. In Afghanistan, their efforts against the Russian troops were often from far away, with shells or missiles.
"Now, in Syria, day by day, they experience head-to-head battle directly. This experience makes them much more able to adapt to war's realities."
By this, Ali means the Syrian alumni, like the Afghan alumni, will carry out terror internationally and will bring home the ability to kill easily; to function under extreme stress; specific expertise in bombs and weapons; and the organisational capability to put complex plots together.
A recent study by the Institute for Policy Analysis of Conflict concluded that the Syrian campaign had "captured the imagination of Indonesians in a way no foreign war has before", partly because of its Sunni versus Shia nature. Indonesia is overwhelmingly Sunni.
Ali is brutally honest about the limits of official knowledge: "We have no idea how many Indonesians are involved in Syria. Several thousand had jobs there before the conflict.
"But we have 17,000 islands, and wide-open sea borders. It's very difficult for us to monitor our people's movements. It's a much easier process now for young Indonesians to get radicalised on social media and to take the step of going to Syria. Previously, recruits had to meet the key people, or spiritual leaders, of jihad groups. Now they don't have to (in order to fight abroad)."
He is also quite blunt about the small but growing minority of Indonesians who support jihad: "There is a large pool of people who are extremists. But the work of the authorities since the Bali bombings has reduced the extremists' capabilities. The worry is that people coming back from Syria will increase those capabilities again."
Ali has two other very specific concerns. One is that there is a large number of Indonesian jihadists completing their sentences and coming out of jail. Nearly 30 such people have re-offended. There is no evidence, Ali says, that more than a handful have been deradicalised. Instead they come out tougher and more determined than ever, often having made new recruits inside.
The other worry is the continuing strength of Jemaah Islamiah, though JI itself is not now conducting violent operations.
"JI is still one of the most dangerous organisations," Ali says. "They look like they're sleeping, but they are building their capability for future action. Their vision of a caliphate for Southeast Asia has never gone away."
And then, finally, Ali expects Afghanistan to go bad when the Western forces leave and to start generating anew its own jihadi training establishments.
This is also uppermost in the mind of Doval, who I interview in a conference room at the Australia India Institute at Melbourne University.
First, though, Doval runs through the list of al-Qa'ida supporting groups in North Africa and the Middle East. It's daunting. Tens of thousands of young men have pledged themselves to al-Qa'ida's ideals. The organisation's central leadership has been hurt but it has mushroomed beyond the wildest dreams of Osama bin Laden into something like a semi-global campaigning force.
"The West sees all these groups as individual problems," Doval says. "But ideologically they are all unified. They all seek to become franchises of al-Qa'ida.
"Al-Qa'ida doesn't have to seek them out. Quite the reverse. Sometimes it rejects them.
"But this acceptance by all these groups of al-Qa'ida as the ideological hub is extremely important. Al-Qa'ida doesn't have a local agenda, it only has a local geography. Its agenda is global."
Doval is especially gloomy about Afghanistan when Western forces leave. "If Pakistan does not support extremist groups it will lose its leverage over Afghanistan, which leverage it believes it needs for strategic depth," he says.
"So if the Pakistanis want influence in Afghanistan, they will believe that they need to maintain influence with the extremists. But you can't help the extremists be strong in Afghanistan and keep them weak in Pakistan.
"If the West cannot keep a credible presence in Afghanistan after the troop drawdown, Afghanistan will have no choice but to rely on Pakistan. Pakistan will try to use this for its own purposes. Pakistan's own internal situation could become much more critical."
The conventional analysis is that al-Qa'ida and the Taliban suffered grievous setbacks because of the post-9/11, US-led invasion of Afghanistan. The Taliban lost control of the Afghan government and dozens of al-Qa'ida leaders, eventually including Osama bin Laden, were killed.
But Doval suggests another way of looking at it: "In 2001, the Taliban was asking for talks (with the US) and saying they had nothing to do with al-Qa'ida. The West at that time thought there was no use in talks and they must crush the Taliban. Now the situation is reversed, the Taliban believe they are the victors and people are asking for talks with them.
"In 2001, al-Qa'ida had bases in Pakistan supported by the ISI (Pakistani intelligence), but it did not have terrorist groups in Pakistan attacking the Pakistani state. Now in Pakistan there is the emergence of many groups which target the Pakistani state and all identify themselves with the cause of al-Qa'ida, even those influenced by the ISI.
"The ISI is hopeful that in the drawdown of Western troops it can leverage its goodwill to stop terrorism in Pakistan. I think the reverse is likely to be the case with the Taliban taking a measure of control."
Doval, like Ali, credits the counter-terrorism efforts of the US and other nations with great successes. But too little attention, they suggest, has been paid to the way the terrorists have adapted.
Let's give an Australian dimension to what Ali and Doval describe. About 25 Australians trained with jihadists in Afghanistan. All those who came back became a security concern. At any time now there are 50-odd Australians fighting in Syria and many more giving other aid there.
Doval says: "We thought the antidote (to global terrorism) was cutting off their finances, and the people's support, but it turns out the antidote was really denying them sanctuaries. They have had sanctuaries in Pakistan in the past. Now if they get a Taliban-influenced government in Afghanistan they could get sanctuaries in Afghanistan again and the situation could be very serious."
He also thinks the talk of splits and differences within the Taliban is overblown. None of the Taliban groups, he notes, ever voices criticism of the overall Taliban leader, Mullah Omar.
In Doval's view, there is a jihadi sanctuary in parts of Syria; pro-al-Qa'ida groups control substantial slabs of territory in North Africa; sanctuaries could easily re-emerge in Afghanistan; and the future of the Pakistani state in the face of jihadi challenge is an open question. It's a crook cocktail.
Doval and Ali are among the best-informed and best-credentialled people assessing global terrorism. Their separate assessments are similar, shocking and deeply troubling. Don't say you weren't warned.