Mark Corcoran is has been a journalist with ABC-TV’s Foreign Correspondent program for 13 years. From 1998-2004 he spent considerable time in Afghanistan, Pakistan and Iran.

I think much of the debate triggered by Sam's post misses a crucial issue: setting aside the 'War on Terror' rhetoric for a moment, if the US-led forces achieve a short-term military victory in Afghanistan, what happens next? Exactly who are Australia and the NATO alliance fighting for? What kind of people are going to run this New Afghanistan?

When you put those questions to US officials over the past several years you got the usual empty, non-specific rhetoric about 'nation-building'. But a key security factor ignored by many in this debate is the simple, indisputable fact that Afghanistan is a narco-state. Half of all economic activity is derived from narcotics.

Kabul April 2009. Investigating narcotics trafficking in Afghanistan, it's easy to make enemies — and not just with the Taliban. Mark Corcoran of ABC-TV's Foreign Correspondent program, with his personal protection team.

I recently spent some time back in Kabul after an absence of five years, catching up with old acquaintances in 'leadership circles', as American diplomats so quaintly put it. What surprised me was not so much the scale of the narcotics trade – Afghanistan has long supplied the bulk of the world’s opium and heroin — but that so many of Afghanistan’s potential leaders are compromised by direct involvement or corruption fuelled by this narco-economy. It felt as though large sections of the government were no longer running a country but a vast criminal enterprise.

The narcotics industry has created an interdependence between 'legitimate' political leaders, the Taliban they claim to be fighting, and the drug barons/warlords. A few powerbrokers in Afghanistan somehow manage to fit into all three of these categories. A new book by US journalist Gretchen Peters, 'Seeds of Terror - How Heroin is Bankrolling the Taliban', does a brilliant job of explaining this interdependence between the 'legitimate' political class, the various insurgent groups that have been labelled with the generic Taliban brand, and of course the drug lords.

Of course, the US has known all along about these narcotics linkages, and sections of the US military and intelligence community have been prepared to turn a blind eye to the drug trafficking of favoured warlords and politicians in return for information on the Taliban and al Qaeda leadership.

This was particularly prevalent in 2002-03. There’s evidence suggesting that these US-sponsored 'blind eye' deals enabled the drug syndicates to not only survive the critical transition of power from the Taliban to the US-led occupation, but thrive under the new leadership, ultimately becoming part of the hydra-headed insurgency problem the coalition faces today. Old American Afghan hands have another term for it: blowback.

I’ve seen detailed Pentagon intelligence reporting on the issue – and broadcast excerpts in a recent Foreign Correspondent report, 'Afghanistan: The Bulldozer', broadcast in Australia in May 2009. This investigation highlighted the exploits of Washington’s favourite warlord, Nangarhar Provincial Governor, Gul Agha Sherzai. When then-Senator Barack Obama made his first visit to Afghanistan last year he bypassed President Karzai and headed straight for a briefing from 'The Bulldozer', as Governor Sherzai is known, for the way he 'bulldozes' his way through political problems.

Only now, nearly 8 years into this conflict, are the linkages between drugs, the insurgency and corruption finally being factored in by US commanders.

Earlier this year I visited the bustling US Drug Enforcement Administration (DEA) base near Kabul Airport. The DEA is ramping up paramilitary operations in Afghanistan to the point where now it even overshadows their presence in Colombia. When I met senior DEA agents they were preparing to change strategy from targeting poppy farmers and middle men and go for the 'kingpins'.

But some veteran DEA agents privately conceded that if they started applying the rule of law, Afghanistan wouldn’t have too many political leaders left. President Hamid Karzai is one of the very few Afghan political figures I’ve met with a reputation for standing above the bog of corruption. But even Karzai’s own brother, a leading political figure in Kandahar, is tainted by alleged links to the drugs trade.

In 2003, I spent two weeks inside the Presidential Palace in Kabul filming a profile of Karzai, attempting to get a sense of the Afghanistan he was trying to build. I accompanied him when he first flew to Islamabad to confront Pakistan President General Pervez Musharraf over the initial cross-border incursions.

Unfortunately, Karzai's credibility was immediately undermined by the 'form' — to use police parlance — of some senior members of his delegation. It was difficult watching Karzai stand there in Musharraf's headquarters, attempting to read the riot act to the Pakistani leadership when everyone in the room knew that members of his own team were heavily involved in cross-border drug trafficking and moving millions of dollars around on behalf of the Taliban. Of course Pakistan’s intelligence agency, the ISI, was also heavily implicated, but that’s another story.

Perhaps the US-led coalition can press on and achieve a costly military victory over the Taliban. But unless this recent shift in US political strategy works, once the victory parade is over, the American generals will still be handing over control of the country to a political leadership indelibly stained by the past. As Thomas Schweich, US Ambassador for Counternarcotics in Afghanistan 2007-08 told me, 'You can't look for lilywhite purity in Afghanistan; it doesn't exist by our standards'.

The tragedy for Afghanistan is that it’s taken nearly 8 years for America’s generals to acknowledge what was obvious from the first day their troops marched through the opium poppy fields — that drugs, the Taliban and the corrupt Afghan leadership are all linked.