If no attack is imminent and Abbott says it is not, then why bother to make the announcement? asks Greg Barns.

Today's announcement by Prime Minister Abbott that he is raising Australia's terror threat level from medium to high should be treated warily. Politicians have a habit of raising fears of terrorist attacks on Australian soil when the evidence suggests that this is a case of rhetoric and reality not meeting eye to eye.

Back in November 2005 former Victorian Premier Steve Bracks and Police Commissioner Christine Nixon announced that an imminent terrorist attack on Melbourne had been thwarted by the arrest of a number of young men and a self-styled sheikh in Melbourne. I acted for one of those men in a subsequent Supreme Court trial in 2008 and can tell you that the evidence presented to the court in that case suggested nothing of the sort. There was no planned terrorist attack by members of this group, just chatter and some bonding activities that made the police and ASIO nervous about their intentions.

Simply because ASIO and police might have heard some talk about terrorism and terrorist attacks by individuals does not mean that those individuals have any means of carrying out an attack. But it will be enough for ASIO and police authorities to jump and tell the PM that a terror alert ought to be issued, because these organisations are suspicious by nature and often read more into things than might actually be the case.

The Prime Minister says that there are people with the "intent and capability" to carry out a terrorist attack in Australia. Of course there are. There always have been and there always will be. Whether that intent amounts to anything and whether the capability is actual rather than simply perceived by jumpy spooks is the question. If no attack is imminent and Abbott says it is not, then why bother to make the announcement?

For political reasons that's why. Nothing like panic and fear to trample liberties and freedoms. Remember the aftermath of 9/11 when the Coalition and ALP both supported appalling new laws that criminalised thought and word in the guise of offences such as support for a terrorist organisation?

This time around Attorney-General George Brandis wants the Senate to pass laws that would see journalists and editors in jail for revealing illegal activities by ASIO and which would protect ASIO from scrutiny when it bugs phones of foreign leaders (as it did in Indonesia) or bugs the cabinet rooms of a neighbour (as in East Timor). Mr Brandis has also mooted draconian powers, such as cancelling passports of Australians travelling to Iraq and Syria if ASIO thinks they might be supporting ISIS in some way.

One of the consequences of Abbott's scare politics will be increased harassment of Australians from the Middle East and of Muslims. The racism and prejudice of Australia is unfortunately tattooed across the underbelly of this land and as we saw when the Howard government reacted to 9/11 it did not take much for irrational attacks on Muslims and Australians from the Middle East to ramp up.

Work carried out the years after 9/11 by Edith Cowan University found:

As a result of personal experiences, Australian Muslims seem particularly susceptible to feelings of fear and anxiety about being objects of concern and suspicion in an increased security environment.

Be very aware of the possibility that the Prime Minister's announcement today is not based on the strongest of evidence but is rather politically useful. Some of us have seen terror threat announcements before and we know that this is an area where politicians and some in the media don't mind gilding the lily.

Greg Barns is a barrister and a spokesman for the Australian Lawyers Alliance. View his full profile here.