Once again, the circumstances were different from those in the months after September 11, 2001, when John Howard invoked the ANZUS treaty to support America in the war on terror, and George Bush coined his "axis of evil" phrase to describe Afghanistan, Iraq and North Korea. But there were similarities, with the Prime Minister preparing the public for an Australian contribution to help avert "a humanitarian catastrophe on a scale unparalleled in recent times" in northern Iraq, and his colleagues talking up "a very real threat to Australia". Evoking Ben Chifley's "light on the hill" speech, Abbott told Parliament: "Our objective is to work 'for the betterment of mankind not only here but anywhere we may give a helping hand', because that is the Australian way – to keep our country safe and to do what we can to build a safer world". There was another echo, too, as Labor struggled to reconcile its responsibility to give bipartisan support on issues affecting national security with the certainty that the Coalition would extract political advantage from the issue. So, when a low-profile West Australian Labor senator, Sue Lines, asserted that the government was "scaremongering" to "try to deflect from the awful mess with their budget", and other Labor MPs made similar remarks, Shorten slapped them down fast.

"I regard, and Labor regards, IS, the Islamic State, as a dreadful, barbarous organisation. We regard them as a threat," Shorten told reporters. "There will not be a debate in this nation in terms of political point scoring from either Liberal or Labor about the importance of tackling this threat." The reprimand was delivered early on Thursday, but not soon enough to dissuade Coalition attack dog, Scott Morrison, from attempting to extract some partisan political edge. In radio interviews, and later in Parliament, the Immigration Minister branded Lines's remarks "pathetic" and called her a "muppet". He also asserted that Labor was responsible for policy settings on border security that allowed the notorious Khaled Sharrouf to leave the country late last year, as if it had on occurred on Labor's watch. In the process, Morrison underscored one of the key dangers for the Coalition: over-playing its hand. Military enterprises like the one in contemplation tend to be electoral winners on the way in, but problematic on the way out. Another concern for the Coalition is that the level of its rhetoric is out of kilter with the commitment that eventually emerges and the real threat of terrorism on Australian soil. Even so, if Coalition MPs began the first week of Parliament after the five-week winter break feeling frustrated, demoralised and let down by their leaders, all for good reason, many were more positive after a week in which the government's almost singular focus was on national security.

There was also better news on another front, with Joe Hockey weathering a Labor onslaught in successive question times – after his gaffe about poor people and petrol – and forcing Labor to change tack by day three. The political question is whether the broader unflattering perceptions of the government that have become entrenched since the May budget will change – and this, in turn, depends on how the Islamic State issue unfolds. While Australia will not do any more or less than what is requested by the US, Abbott has been careful to all but rule out "troops on the ground", insisting any contribution will be in the context of "achievable objectives, a clear role for Australian forces, a full risk assessment, and an overall humanitarian objective". For a politician defined by his performance as Opposition leader, his social conservatism and his unpopular budget, Abbott is finding foreign affairs a liberating place, where legislation or the approval of the states are not required, and where his views on good and evil sit neatly with his perception of Australia as a global player for good. But the truth of it is that Australia is a peripheral performer when it comes to confronting what Abbott calls the "witches' brew" of complexity and danger in the Middle East, and that, even in foreign affairs, there are higher priorities, closer to home.

Perhaps the biggest difference, and there are many, between the situation facing Abbott now and Howard's response to 9/11 in 2001 is that the next election is two years away, not two months. For all the focus on national security, there was little this week to allay Coalition backbenchers' concern that they are excluded from decision-making, and that those in charge have a tin ear when it comes to reading the mood of the electorate. There was also the contained storm over Abbott's explanation for being late to Tuesday's first partyroom meeting in months (he was reported as saying he had visited a Melbourne cancer hospital that morning to ensure that a trip to a private fund-raiser the previous night was within by travel entitlements). As Niki Savva, Peter Costello's former right-hand woman, wrote in The Australian, it was a moment of madness brought on by poor planning, extreme tiredness and provocation". The biggest reality check for Coalition MPs, however, is that, for all the focus on national security, the Senate impasse over unpopular budget measures such as the GP co-payment remains. As Monty Python might say, the impasse ain't dead; it is just resting. Michael Gordon is political editor of The Age.