When President Obama announced last week that he was sending an additional 17,000 troops to Afghanistan, I thought of David Kilcullen.

Kilcullen is a former Australian military officer who wrote his doctoral thesis on insurgencies in traditional societies. I first met him in June 2007 in Baghdad, where he was senior counterinsurgency adviser to Gen. David Petraeus and helped design the strategy that tamped down Iraq’s violence.

Kilcullen laid out the sequence of that strategy for me, illustrating his points by drawing a diagram on a white erasable board. Every piece of that diagram panned out over time just as he had projected (the famous troop “surge” was only one element of the strategy).

So I thought this would be a good time to phone him and ask about future strategy for Afghanistan.

It quickly became clear that the Afghan mess makes Iraq (even at its worst) look simple. But before I get to Kilcullen’s proposals, a little history is in order.

Obama inherited a scary mess from the Bush administration. Seven years after the United States invaded Afghanistan in the wake of 9/11 and successfully ousted the regime that had hosted Osama bin Laden, it’s clear that our victory there was squandered.

While the Bush team focused on Iraq, the Taliban made a comeback in Afghanistan, and, along with al-Qaida, established a haven across the border inside Pakistan. Perhaps 70 percent of the country has become off limits to Afghan security forces; NATO troops are too few, and too conflicted about their mission, to stop the Taliban’s expansion.

So Obama is conducting a series of major strategy reviews aimed at producing a new approach to Afghanistan — and Pakistan — before a crucial NATO summit in early April. Kilcullen, who’s now a fellow at the Center for a New American Security think tank, worked on one just-completed review under Petraeus.

Now to his main points:

1. Yes, we need to be in Afghanistan, even though Americans are rightly worried about the cost in lives and money. We can’t afford to let Afghanistan become another Taliban-run sanctuary for al-Qaida, which could lead to another 9/11.

2. Yes, the bigger problem is across the border in Pakistan’s tribal areas, where al-Qaida leaders are based. “We’ve focused on Afghanistan,” Kilcullen says, “because we have troops there. But the real problem is in Pakistan; the real threat is the collapse of a state with 173 million people, 100 nuclear weapons, an army larger than the U.S. Army, and Osama bin Laden waiting in the wings” to get his hands on those nukes.

So any Afghanistan strategy must focus on the entire region. That includes diplomacy to try to strengthen Pakistan and turn its leaders’ attention from India to the internal terrorist threat to its survival.

But in the meantime, something must be done to prevent more of Afghanistan from falling to the Taliban, which would increase its ability to threaten Pakistan next door.

3. Yes, the additional U.S. troop numbers are far from sufficient. So the use to which those new troops are put becomes even more crucial.

In other words, as in Iraq, it’s the strategy, stupid (my words, not Kilcullen’s). Despite the many differences from Iraq, there is a key similarity: We must focus on protecting the Afghan people from Taliban intimidation, while helping them develop their own security forces and improve their living standards.

Instead of doing that, says the Aussie, “we’ve been chasing the Taliban main force out in the countryside, while the Taliban underground cells intimidate the population where they live.”

To use the new troops effectively, he continues, we need to change focus. “The key word for Afghanistan is triage,” he explains. “We need to figure out where the bulk of the population lives and how to secure the major population centers, not just towns, but major villages.”

U.S. forces should be out in the community, working alongside (and training more) Afghan army and police to support local officials and secure delivery of services. In areas where the Taliban threatens, but we can’t send U.S. forces, we should “put special forces in partnership with local neighborhood watch groups.”

He adds that Afghan tribal structure is far different and less hierarchical than in Iraq, and has been broken down through war, so we can’t rely on tribes as militias. “We should use local forces,” he says, “based on districts, not tribes, for village defense. Make the population self-defending in partnership with us and the government.”

In other words, help Afghans help themselves. And, as in Iraq, protect “oil spots” of territory until the population feels secure. Then expand security outward from there.

4. Yes, there is no purely military solution to Afghanistan. Afghans need institutions that provide them with basic necessities of living, but a corrupt central government can’t seem to provide them. So U.S. efforts at reconstruction should be local, local. “We’re focused on building national institutions in Kabul, while the Taliban focuses on establishing control at the local level,” says the strategist.

To sum up, Kilcullen says we should Prevent (Taliban take-over), Protect, Build, and ultimately Hand-off to the Afghans. Given his prescience on Iraq, his ideas on Afghanistan deserve attention.