Australia and its allies did not have a strategy or defined goals in Afghanistan and are now struggling to find a way out, says the former chief of the army, Peter Leahy. 
The retired lieutenant-general has written in an opinion article for Fairfax Media that the US-led coalition's determination to get out of Afghanistan "ready or not" has been a failure because ,despite a 15-year Western military presence, the security situation is once again sliding backwards.
"We are still struggling to find an exit strategy," Professor Leahy writes. "Over time, our politicians did not tell us much of our strategy. There is a good excuse - we didn't have one."
He said that though the initial mission was clear - to punish al-Qaeda and topple the Taliban who supported them - the coalition then embarked on "tightly constrained successive missions" and "struggled for a strategy".
"Then, after 13 years, we decided on leaving the country 'ready or not'.
"Even that didn't work and, due to a worsening security situation, the withdrawal has been put aside and around 270 troops remain in Afghanistan today - seemingly tied to an American presence in the country."
Professor Leahy, who now heads the University of Canberra's National Security Institute, said in an interview that counter-insurgency experts believed a project such as Afghanistan should consist of 80 per cent civilian reconstruction and development and 20 per cent military.
"No one can tell me it was anything like that," he said. "I don't think we even knew what our ends were. We never saw what people kept saying should have been a 'whole-of-government' response. We never saw that in terms of adequate political and diplomatic resources. It was almost a set-and-forget way in our military response."
He said a "bugbear" for him was that the strategy had never been properly debated by Parliament.
Professor Leahy was speaking ahead of a new documentary set to begin on the ABC on Tuesday night about Australia's involvement in Afghanistan. He said the program would redress the lack of in-depth reporting, which had been partly the result of media coverage being "tightly controlled".
The Chief of the Defence Force, Mark Binskin, told a Senate hearing two weeks ago that "the overall security situation deteriorated" in Afghanistan last year. In several rural districts in Oruzgan province, where most Australian troops were based until the end of 2013, insurgents had "increased their freedom of movement and generally contain [Afghan] units to their bases and checkpoints".