The definition of a ‘terrorist act’ included in Australia’s Criminal Code since 2002 has been important in protecting Australia’s national security and reinforcing the resilience of our democratic institutions. That definition, currently the subject of an inquiry by the Independent National Security Legislation Monitor (INSLM), continues to be relevant and effective. It should be retained with minimal revision.

We welcomed an opportunity to engage with the INSLM to discuss the definition of a ‘terrorist act’ as outlined in section 100.1 of the Criminal Code Act 1995. Our subsequent submission to his inquiry reflects a policy and operational perspective grounded in the realities of operational and strategic counterterrorism, rather than a legalistic or academic critique.

Since its introduction, the terrorism definition has been reviewed seven times by different institutions and jurisdictions, yet no substantive amendments have been adopted. One interpretation might be that the number of reviews and recommendations reflects some kind of failing. We suggest that it instead reflects the reality that recommended revisions have simply not had public nor political support.

We reject the premise that absence of change implies deficiency. The burden of proof lies with those advocating for revision to demonstrate that an alternative definition would better serve Australia’s interests by being more effective, more proportionate, more protective of rights and more consistent with international obligations. To date, no such case has been convincingly made.

A core strength of the current definition is its inclusion of a motivational element: that a terrorist act must be committed with the intent of advancing a political, religious or ideological cause. This is not a semantic flourish; it’s foundational. As our submission notes:

Terrorism is first and foremost a crime directed against the state and the nation, regardless of the specific target of the action or threat. Terrorism’s unique effect on society and government makes it particularly damaging to social cohesion within a democracy. For terrorism is an exercise in the negation of politics—in so far as violence for political, religious or ideological purposes within a constitutional democracy and society simply cannot be tolerated. It represents an unacceptable challenge to the lawful monopoly on violence by the democratic state. All the other ills (including the terrible harms visited on people or the population) are important but secondary to this point.

Some have proposed removing ‘religious’ and ‘political’ motivations, arguing that ‘ideological’ alone is sufficient. We disagree. In an era of increasingly mixed and hybrid motivations—where attackers may be driven by a blend of grievances, ideologies and personal pathologies—narrowing the definition would be counterproductive.

The inclusion of ‘religious’ motivation is necessary for the definition’s operational functionality. The INSLM inquiry’s own issues paper finds that nearly 95 percent of terrorism convictions in Australia have involved religious motivation, predominantly linked to Islamist extremism. This is not a function of the law’s wording, but a reflection of the threat environment.

Aspects of Australia’s terrorism threat landscape have changed significantly since 2002. The rise of online radicalisation, proliferation of lone actors—often minors—and emergence of new ideological drivers such as misogyny and ethnonationalism have reshaped the operational environment.

In our view, these changes reinforce, rather than undermine, the need for a broad and flexible definition. The current framework accommodates this complexity. For example, ASPI’s past research into misogynist incel ideology demonstrates how emerging threats can potentially be captured under the existing legal structure when they are ideologically motivated and violent.

The law is not responsible for the social conditions giving rise to radicalisation. It is, however, central to enabling early intervention and disruption, especially when warning times are shrinking.

We support the current exclusion of ‘advocacy, protest or dissent’ from the terrorism definition. However, we caution against further expanding this exclusion, as some have suggested. In a time of worrying political polarisation and attempts to legitimise politically motivated violence in democratic societies, weakening this boundary would be unwise. Serious property damage, when committed with terrorist intent, must remain within the scope of the law. Terrorism is about intent and effect, not just physical injury.

We are not opposed to all change. There are opportunities for limited, sensible improvements that preserve the law’s intent and operational utility. These include potentially:

—Expanding the definition of ‘harm’ to include psychological harm, aligning it with other legal contexts;

—Explicitly including hostage-taking and kidnapping as terrorist acts to aid prosecution; and

—Separating terrorist acts and threats into distinct offences, while not inadvertently disincentivising agencies from acting early and precisely to disrupt threats.

These refinements would enhance clarity and prosecutorial effectiveness without compromising the effective operation of the law.

Australia’s terrorism definition has stood the test of time. It has enabled security agencies and police to act decisively and proportionately in the face of evolving threats. It has not eroded civil liberties in any demonstrated, substantive way, and it continues to enjoy public and parliamentary support.

In a period marked by social division and rising extremism, now is not the time to weaken the legal foundations of Australia’s counterterrorism framework. We encourage the INSLM to prioritise operational effectiveness and national resilience in his considerations. The current definition is not perfect, but it is principled, practical and proven.