When he takes office today, Barack Obama will inherit a situation in Afghanistan that is growing increasingly complex. Mr. Obama has made success in the war there a key element of his foreign policy, so it’s important for the new administration to understand the current facts on the ground. American policy there is due for a rethink.

Since 2007, the war in Afghanistan has undergone a dramatic shift, from large-scale attacks to more asymmetric terrorist assaults and roadside ambushes. Pro-Taliban militants attack those perceived to be in support of the Afghan government — namely, U.S. and North Atlantic Treaty Organization forces and humanitarian aid workers. The Taliban’s aim is not direct confrontation, but rather a protracted war of attrition that will gradually expand their political and economic influence. Defeating the spreading Islamist insurgency depends on the coalition’s commitment to increase the Afghan government’s ability to improve security, deliver basic services and expand development for economic opportunity.

But the biggest challenge here will be to reconcile the imbalance between what Afghanistan is — a complex tapestry of traditional tribal structures — and what we want it to be — a burgeoning nation-state governed centrally from Kabul. Containing the insurgency will require working with local leaders to ferret out militants. Unfortunately, these local leaders in far-flung provinces have limited contact with the central government institutions in which the coalition has invested the most time and resources. Overall, the coalition must move away from focusing solely on the country’s national institutions, such as the Afghan National Army, and devote more to increasing security at the district and provincial levels.

One way would be for U.S. and NATO forces, in cooperation with the Afghan government, to provide tribal councils with more opportunities for economic development and greater autonomy in running local affairs. In exchange, tribes would be encouraged to recruit men for Afghan local security forces and to evict insurgents rather than provide them shelter.

Such an approach gradually pries the loyalties of indigenous people away from extremists, helping to weaken the Taliban’s ability to exploit tribal rivalries. It will also involve negotiating with at least some groups that oppose the coalition’s presence. This approach might work by separating militants who fight for money — what U.S. Central Command Chief General David Petraeus referred to as “reconcilables” — from the more intractable Islamist elements of the insurgency.

There will certainly be risks in adopting this new approach. Dialogue with rank-and-file insurgents is unlikely to persuade senior Taliban leadership to renounce violence or stop recruiting. It will also be difficult to distinguish the “reconcilables” from others. Afghanistan’s tribal networks are complex and in some areas (mainly along the eastern border with Pakistan) constantly shifting. U.S. and NATO forces are already having difficulty telling ordinary tribesmen from militant operatives. But if the coalition is to make further progress securing the country, there is little alternative but to try.

Success in Afghanistan also depends on how the war on opium poppies (the source of heroin) is conducted. Drug trafficking accounts for some 60% of the country’s economy. Crop eradication and the destruction of drug processing facilities was a high priority of the Bush administration and may continue to be under President Obama. The United Nations estimates that 500,000 families are involved directly and indirectly in the drug trade — about 35% of the population. This figure includes both enemies and allies of the coalition.

Unfortunately, the war on drugs is interfering with the U.S. effort to neutralize the spreading insurgency. Policy makers must recognize that the Taliban exploits popular resentment against eradication efforts, and should target large-scale traffickers affiliated with al Qaeda and the Taliban instead of poor peasant farmers.

Nor can the coalition afford to ignore Pakistan and India. If the Pashtun and Baluchi areas of Pakistan did not act as de facto sanctuaries for the senior leadership of al Qaeda and the Taliban, the war in Afghanistan would have a very different character. In the short-term, a small number of U.S. Special Forces personnel could support local Pakistani security forces in the implementation of low-level “clear and hold” operations along the Afghan-Pakistan frontier to limit cross-border movement. In the long-term solution, India and Pakistan need to broker a more permanent peace settlement.

The coalition has made great strides in Afghanistan since October 2001, not least in ousting the Taliban from central power. National-level progress such as an improving Afghan army can pave the way for peace. But these steps will not be enough on their own. It’s up to a fresh administration in Washington to bring fresh thinking to bear in Afghanistan.