This week a Sydney man, Mustapha Al Majzoub, was killed in Syria, apparently by government rocket fire. His family says he was in Syria doing humanitarian work. Media reports said he was known to police and intelligence services because of his extremist views.

There is no need to doubt the humanitarian work of this individual to see that his case nonetheless points to several very big security problems emerging out of the Syrian conflict, and the Arab Spring more generally.

For Australia, these are quite specific problems. But the Arab Spring has also produced a series of new and perplexing dilemmas for security and counter-terrorism forces across the Western world.

In Sydney and Melbourne, police are worried about the tensions ignited within the Arab Muslim community by the conflict in Syria. This especially affects Australians of Lebanese and Syrian background, and has led to tension between Sunni and Shi'ite Muslims, and between Sunni and Alawite Muslims.

Bashar al-Assad's regime in Syria is based on the Alawite minority. There is also a significant Alawite minority in Lebanon.

In both Syria and Lebanon, there has been murderous sectarian conflict along these communal lines.

Police forces are worried at the intensity of these derivative hostilities within Australia. These are not jihadist-based conflicts, but straightforward sectarian enmities.

However, the civil war in Syria is having serious global jihadist consequences and Australian developments will be a part of this.

A small but significant number of Australians have gone to Syria to participate in bringing down the Assad regime.

No doubt many of them have good, democratic motivations. And it is unclear how many, if any, have been involved in actual fighting. But this travel cannot be divorced from the global inflow of jihadists to Syria. The Syrian conflict of today has become, on a smaller scale, the Afghanistan of the 1980s, attracting jihadists from all over the world.

The biggest pipeline for al-Qa'ida affiliated extremists into Syria is from Iraq, and mainly involves the al-Qa'ida in Iraq movement. It uses the same networks and lines of communication that Syria once used to send extremists into Iraq to hurt the US efforts there, but this time the flow is reversed. At the same time, there is a good deal of movement of people between Lebanon and Syria.

The number of Australians involved in the fighting in Syria is likely to be very small. But it is impossible to know precisely, because there is always a big traffic of Australians back and forth to Lebanon visiting family. Almost all of this travel is entirely innocent.

But if people go on to Syria to oppose Assad they are bound to meet and mingle with the jihadists flowing in. As the situation in Syria becomes more violent, opposition to Assad is more likely to involve military and paramilitary activity. When they come back to Australia, will they be influenced by this experience? Will they have acquired training in weapons and explosives? Will they bear the imprint of jihadist ideology?

It is still reasonable to hope that the revolutions unleashed by the Arab Spring may result long-term in a more representative, accountable, democratic and moderate political culture in the Middle East.

This is by no means assured - or even the most likely outcome - but it is certainly worth working for. However, if you were to make a net assessment today of whether the Arab Spring has increased or decreased the terrorist threat, the assessment would have to be that in the short term it has made things worse. This is especially because of developments in Libya, Egypt and Syria.