While Tony Abbott’s justification for not visiting Afghanistan is the sort of thing that would earn a Labor Opposition leader a week of contumely from shock jock and earnest op-ed writers, it’s a non-issue in the scheme of things. Indeed, there’s something to be said for not having the Prime Minister and the alternative prime minister flying into the same war zone on the same flight.

Nonetheless, the Coalition — or more accurately its Defence spokesman David Johnston — is not being particularly helpful on Afghanistan. There is clearly a difference between Abbott and his shadow minister, with Abbott this morning taking pains to emphasise the bipartisan nature of policy on Afghanistan, rather than endorsing Johnston’s view that the Government should be taking its advice from soldiers on the ground and significantly ramping up our Afghanistan presence, rather than listening to the ADF top brass.

Abbott is wise to do so, because public opinion on our involvement in Afghanistan is strongly opposed to it, and divisions between the major parties are only going to increase the likelihood that public opposition firms up into something more actively hostile to our role.

It’s tempting to see the Coalition as playing politics over our role but Johnston’s comments, after the controversy over a soldier’s email criticising the ADF after the firefight on August 24, might instead — or also — reflect an emerging dispute over the nature of our role in Afghanistan and differences between the Defence hierarchy and soldiers on the ground.

“People assume that because a Digger says something, it’s true, but it’s just one perspective,” Neil James of the Australia Defence Association told Crikey (the ADA has a detailed and very clear account of both the email controversy and the issues it raised). “And your perspective depends on what you think our operational missions should be. If you think our mission should be to secure Oruzgan province and destroy the Taliban, you’ll think we need much higher force levels. If you think our role is to mentor Afghan forces, then you’ll think the force level is about right or needs only a small increase.” (The ADA believes the mentoring force should be increased by about 150 troops).

James also says there’s a generational divide between the ADF hierarchy, who came up during the peaceful years of the 1980s and 1990s, and the current generation of servicemen who have extensive combat experience. “This is more than just a communications problem, which the ADF thinks it is. It’s a cultural problem.”

There’s a growing view — a twist on the much-mocked “good war” thesis — that we should end our role in Afghanistan because the West lost its opportunity to destroy the Taliban and establish a viable Afghan state when we launched the assault on Iraq. Charles Richardson articulated this view in Crikey last week. And yes, Julia Gillard, like Barack Obama and David Cameron and other leaders with forces on the ground in Afghanistan, has to make decisions about our future involvement in that country within the framework of the disastrous strategic blunder of Iraq, which has made a tough war in Afghanistan vastly more difficult. But like those who oppose the war outright, whether on the basis of reflexive anti-Americanism or for any other reason, that argument fails to acknowledge the reality that Australia is currently on the ground in Afghanistan and is playing a specific role that serves the broader strategic rationale for why we participated — correctly — in the removal of the Taliban in the first place, to ensure Afghanistan does not serve as a state sponsor of terrorism on a vast scale. There are no options for Australia’s role in Afghanistan free of serious consequences. The withdrawal of Australian troops would further reduce the already limited prospects for a stable Afghanistan.

Neither side of politics has been able to convincingly argue this strategic rationale to Australians. Perhaps that was an impossible task anyway — judging by the views of Americans and Britons, US and British leaders have been no more successful than John Howard, Kevin Rudd and now Julia Gillard is convincing people that we need to be in Afghanistan. But David Johnston’s efforts only serve to fragment what’s left of the major party consensus about how we fulfill our responsibilities in Afghanistan.