The question is: do the changes to the Crimes Act and the associated anti-terrorism measures announced by the Prime Minister last week suggest a Government that is more alarmed than alert, or are they further evidence of political virtuosos who can spin the community's security concerns into political advantage? The answer is: it is a bit of both. But where alarm and spin combine to constrain personal freedoms without having much impact on the problem - terrorism - the community has reason to worry.

It is clear that the alienated radicals forming the splinter groups within international Islam are a threat to personal and national security, though the level of threat may well be overstated. Random acts of violence, whether remotely triggered explosions or suicide bombers, give people the jitters. Commuters bear the brunt of this unfocused fear, and governments have every reason to strengthen public safety measures on underground trains, the ferries, in bus and rail concourses and at airports. So closed circuit television, facial recognition software, a heightened security presence, improved passenger flow management and security drills are all reasonable, if expensive, responses that most people would support.

Greater intrusion into people's private affairs notwithstanding, the adjustments to the warrant system through which ASIO exercises its surveillance and monitoring powers are also reasonable. That is because that process demands reasonable grounds for the warrant and accountability on the part of the decisionmaker. And, what is of equal importance, the warrants have a termination date, thereby requiring review and re-issue if surveillance is to continue. In my experience, ASIO and successive attorneys-general have handled these matters with care and diligence. Although they might make us bristle at the inexorable march of "Big Brother", these are essentially administrative matters that the community can tolerate.

The proposal that it become an offence to incite violence within the Australian community or violence against our forces deployed overseas probably makes sense, even though the difficulty of proving incitement should not be underestimated. As we saw in the Spycatcher appeal in 1987, the courts take the view that "freedom of speech and disclosure of information (should) not be unnecessarily or unreasonably curtailed". Nonetheless, while a charge of "sedition" would be difficult to uphold, the provision would impose a serious constraint on those who advocate terrorist acts.

Of greater concern are the other proposals for legislative change that significantly increase the powers of government and the bureaucracy to constrain or curtail personal freedoms. Apart from the civil liberty and jurisprudence issues, we need to ask ourselves whether the threat is actually serious enough to warrant these changes, and whether they will be effective anyway.

Serious doubts attach to legislation permitting control orders, preventive detention, notice to produce and the extension of stop, question and search powers. Indeed, such powers, if targeted against the communities that might harbour terrorist sentiments, are more likely to exacerbate the problem than alleviate it.

What these measures fail to grasp is that terrorist cells cannot be eliminated using the traditional tools of legislation and law enforcement. They are not like criminal conspiracies that have structure, leaders, management and bureaucracy. Terrorist cells are ephemeral: they coalesce around specific terrorist operations, then mutate as other opportunities appear. They are opportunistic rather than targeted, which explains why terrorist events cannot be prevented absolutely. What governments, acting co-operatively, must do is to attack the causes and motives of terrorism by addressing the issues that alienate vulnerable communities and generate radicalism.

Australian governments have traditionally shied away from granting what are tantamount to royal commission powers to the police. The scope for abuse is too great. Yet the apparently unlimited scope of the notice to produce "information that will assist with the investigation of terrorism and other serious offences" has the potential to undermine both legal professional privilege and the protection of media sources. Similarly, the preventive detention proposal is far too open-ended, and lacks any sunset provisions that would remove it from the statute books when it is no longer needed. What is more alarming, however, is that these stern measures are unsupported by argument and evidence of threat. Nor is there any analysis of their likely effectiveness. And accountability is totally overlooked. It is here that one might suspect the victory of politics over reason.

Australia will not be more secure by becoming less free: our real defence is the rule of law, inclusiveness and prosperity.