By Gordon Corera
BBC security correspondent
Australia has never been hit by a major terrorist attack.
Suspects were arrested in Sydney and Melbourne
But as with London before 7 July, there has been a sense of inevitability in some quarters in Australia that something would happen.
In this case, police say they have foiled an attack in the making.
And their actions may well heighten debate, both in Australia and in the UK, about what powers the police should have.
Australia's strong support for US President Bush's war on terror, and particularly its commitment of troops to Iraq, put the country squarely in the firing line for al-Qaeda and its sympathisers.
And Australians have been targeted outside of their country, most notably in Indonesia with the 2004 attack on the Australian embassy in Jakarta.
Osama Bin Laden made clear that Australia was a target in a November 2002 statement, singling it out for joining in the Afghanistan campaign and also for its intervention in East Timor.
Another statement by Bin Laden in October 2003 also singled out those states contributing troops to Iraq. The UK, Spain, Australia, Poland, Japan and Italy were all named and officials in most of those countries have either seen attacks take place (the UK and Spain), foiled attacks (Australia), or been extremely jumpy about the possibility (Italy).
A small number of Australian individuals, including converts to Islam, have also been accused of becoming involved with al-Qaeda or attending training camps.
Australian police have been talking to their British counterparts in the wake of the London bombings of 7 July to see what lessons could be learned.
There are some interesting parallels between recent events, with the alleged Australian group also looking to be home grown and allegedly having bought similar types of chemicals as those used in the London explosives. Iraq again looks to have been one of the motivating factors.
The Australian arrests are also likely to heighten domestic and international debate over anti-terrorist legislation.
Only a few days before the arrests, Prime Minister John Howard warned that an attack could be imminent. His statement generated some controversy since it came in the middle of a debate over new counter-terrorist legislation and some claimed he was exploiting intelligence to gain advantage.
John Howard has been warning Australians of the terrorist threat
Mr Howard said the amendment he proposed would make it easier to prosecute suspects believed to be involved in the early stages of planning attacks, since it allowed arrest even when the exact nature and target of a terrorist act could not yet be identified.
He has now said that the need for passage of this new power has been vindicated by the latest arrests, which utilised these new powers.
The problem for all police forces is trying to work out at what stage to intervene as it becomes clear that a group may be considering a terrorist attack.
Move too early, and there may not be enough evidence for a criminal prosecution and conviction; leave it too late and there is a risk of allowing an attack to take place, especially when in practise police and security services may not be confident they know everything about a group's activities or everyone who is involved.
Is collecting information on how to make explosives the right point at which to move? Or ordering large amounts of chemicals? Or carrying out reconnaissance of a target?
These tensions have been the driving force behind police and officials requesting new powers in order to be able to either charge individuals with new offences such as acts preparatory to terrorism, or to be able to hold them without charge for longer whilst evidence for a case is collected.
However, critics of the UK proposal to extend detention without charge to 90 days may well point to Australia, where the new proposed legislation extends the period to 14 days for detention without charge.
And the debate in Australia over balancing civil liberties and security has been as heated as that in the UK, although the dynamic may now change as a result of these arrests.
Australian officials have indicated that the men were under surveillance for a period of years, not just weeks or months. All that time, evidence was being gathered and the group closely watched to determine how close they might be to actually executing - rather than just planning - an attack.
Eventually, a decision was made to move against them rather than wait any longer.
Ken Moroney, New South Wales Police Commissioner, told Australia's ABC Radio: "I don't believe that the law enforcement agencies were prepared to take that risk any longer. Not a case of 'Let's wait and see when it goes off and where it goes off.'"
During this time, and in the largest counter-terrorist operation in the country's history, the men's communications are reported to have been intercepted for clues.
In Australia, unlike the UK, phone-tap evidence has been admissible in court for decades and is regarded as invaluable. Some question why UK officials say they need more time to collect enough evidence against suspects before charging them, but still resist allowing intercepted communications to be used as part of the case.
In the wake of the new legislation and the arrests, police in Australia are trying to send out a message to the Muslim community that it should not see itself as being victimised.
But the arrests are bound to heighten concerns on all sides about further possible plots.
And although police have said it was not the intended target, the Commonwealth Games due to be staged in Melbourne next year are likely now to see even more intense security.