The new five-level National Terrorism Threat Advisory System has come into operation, placing the current threat of an attack in Australia as “probable”.
But agencies stress there has been no actual change in the threat level, which was characterised as “likely” under the old, more limited classification.
The levels under the new system, allowing for greater nuance, are: certain (red), expected (orange), probable (yellow), possible (blue) and not expected (green).
The new system replaces a four-tier ranking: extreme, high, medium and low. The level was raised to high in September last year.
The threat level is based on assessments from the National Threat Assessment Centre within ASIO. Any change is advised by the head of ASIO.
Whenever the government alters the threat level, it will explain the change to the public. No change has been made in the wake of the Paris and other recent attacks, although a government background paper says that some of the factors underpinning last year’s decision to raise the level “have worsened”.
Attorney-General George Brandis and Justice Minister Michael Keenan said on Thursday: “we face one of the most significant threats from terrorism in our nation’s history”.
The “probable” threat level means credible intelligence indicates individuals or groups have developed both the intent and capability to conduct a terrorist attack.
The government paper says the “radicalisation and recruitment of Australians is increasing. Violent extremists are reaching out to those willing to listen and encouraging them to either join ISIL or to conduct attacks in its name”. The small number of Australian-based Islamic State supporters might be emboldened by the perceived success of the attacks abroad, it says.
“Elements of some of these recent attacks, such as the use of firearms and explosives as weapons, the capturing of hostages, and the focus on ‘soft’ targets, could be employed in an attack in Australia”.
The paper says that while symbols of government and authorities perceived as terrorist adversaries – the military, police and security agencies – were often terrorists’ targets, indiscriminate attacks were increasing, and the risk to the general public in Australia remained.
“The most likely form for a terrorist attack in Australia would be an attack by an individual or a small group of like-minded individuals, however a larger, more co-ordinated attack cannot be ruled out,” the paper says.
“It is highly likely that a terrorist attack in Australia would use weapons and tactics that are low-cost and relatively simple, including basic weapons, explosive and/or firearms.”