TONY Abbott today fought back at claims of a “chaotic” and misguided approach to military deployments during his term as prime minister, calling them “fantasy”.

Former Australian officer and military strategist James Brown launched a scathing assessment of Abbott in the just-released Quarterly Essay, “Firing Line”.

“Abbott’s stewardship of the ADF presents the clearest case in recent times of a prime minister struggling to grasp the limits of Australian military power,” Mr Brown said.

But Mr Abbott fought back on Twitter today stating: ”James Brown’s claims about military adventurism by the Abbott government are just fantasy”.

Mr Brown, who is Malcolm Turnbull’s son-in-law, argues that prime ministers have too much individual power to take the country to war, and that parliamentary and public debate is stifled, says Mr Abbott initially appeared to impress as a commander-in-chief.

Camera Icon Ex-PM Tony Abbott is campaigning to hold onto his seat of Warringah. Credit: News Corp Australia, Hollie Adams/The Australian

But six months on, Mr Brown, who served on numerous deployments, writes that Mr Abbott had begun plotting “the riskiest of missions”.

The first was a unilateral plan that involved readying special forces to intervene in the kidnapping of schoolgirls in Nigeria by Boko Haram.

“This was an expansive and dangerous task for Australia to perform in a country with which our military had little familiarity and where our country had few direct interests,” Mr Brown writes.

When Malaysia Airlines MH17 was downed over the Ukraine in 2014, Mr Abbott considered deploying a battalion of 1000 troops, against the advice of military planners.

“The logic of deploying large numbers of troops into an active war zone alongside the border of a major global military power (Russia) was entirely shaky,” said Mr Brown.

He reveals that military advisers were working up options for Mr Abbott to deploy up to 3000 troops to the Ukraine, which would have put them at war with both Russia and the separatist movement in eastern Ukraine.

Mr Abbott then began looking at a large deployment to Iraq. Mr Brown says Mr Abbott calculated the best way “to encourage the United States to retain an active role in world affairs was for Australia to lead by example”.

This lead to chaos in Australia’s military institutions as they tried to keep up with Mr Abbott’s desire that Australia step into conflicts on three continents.

“He pushed Australia’s small defence force and decision-making structures to their limit,” writes Mr Brown, adding that he “overcomitted Australia’s special forces” which left little reserve forces at home should a crisis arise.