The savage terrorist murder in London of British soldier Lee Rigby, a Royal Fusilier, an Afghanistan war veteran, a husband and father, has once more shocked Western sensibilities.
The typical reaction is to describe the murderers as madmen.
In fact their action, and the chilling, surreal way one of the men explained it straight afterwards, is wholly evil but perfectly rational.
They see themselves as part of a historic religious and political war against the infidels, the West and all those whom they see as fighting Muslims anywhere. They are no more irrational than the equally murderous Islamist terrorists in Pakistan or right across North Africa.
In societies such as Britain, the US and Australia, with stable, affluent societies and superb, well-resourced security services, terrorist deaths have been kept to a minimum.
But before we trivialise the threat, we should recall that there have been 23 convictions for terrorist offences in Australia. Some of the plots revealed involved plans to attack Australia's research nuclear reactor and to inflict mass death at army barracks.
We also should remember that in one single terrorist attack in Bali, 88 Australians were killed.
The West is in danger of thinking that the war on terror is over and that those who hate our society have gone away, lost interest in us or given up the struggle.
Nothing could be further from the truth. The reaction to 9/11 brought an intense counter-terror effort in the West that has been remarkably successful, overall, in securing Western homelands. But things are starting to look quite a bit worse just now. This derives from the events in Syria and North Africa.
Of course, Syria is primarily a tragedy for the Syrian people.
The Syrian civil war is in its third year. Perhaps as many as 90,000 people have been killed.
About 1.5 million Syrians are refugees in nearby countries. Western intelligence agencies believe that as many as seven million Syrians eventually may flee their homeland.
This is a devastating humanitarian tragedy. It will also have implications for terrorism.
Syria is becoming a new ungoverned space that is attracting thousands of jihadists, as did Afghanistan a generation before. In Syria, these people will taste blood, learn terrorist skills and deeply internalise the most radical Islamist world view.
Many of them will then return to the Western nations of which they are citizens. Who knows what the results will be?
Australian security agencies believe that 200 Australians are in Syria participating in the civil war. Some are involved with Jabhat al-Nusra, the most effective fighting group in the Syrian opposition. Jabhat al-Nusra has publicly pledged its allegiance to al-Qa'ida.
Al-Qa'ida may be much weaker than it was as a central organisation - mainly because so many of its leaders have been killed by US drone strikes - but it remains a powerful brand, and organising principle, among jihadists.
The Western response to the Syrian crisis, which really means the US response to the Syrian crisis, has been feeble. But the US has no good options. Australia has done what it can by donating humanitarian aid to the Syrian opposition and to Syria's neighbours coping with the refugee flow. This is good work and the Gillard government has certainly done the right thing here. But broader allied policy, which again really means US policy, is ineffective.
