Afghanistan is poised on another crossroads fraught with challenges after a difficult, if peaceful, power transition following an acrimonious contest of the presidential poll results.

The new government took a positive step forward by signing two security pacts - allowing 10,000 US troops and another 2,500 Nato soldiers to remain in a training and supporting role beyond their end-2014 pull-out - that would help keep the Taleban forces at bay.

But it could be downhill from here if the national unity government proves to be anything less than that. And there is a possibility the government could come unstuck, given the circumstances under which it arose.

After months of wrangling following the April polls, a deal was struck with US mediation that was shrouded in secrecy. Mr Ashraf Ghani, a former finance minister, became president and Mr Abdullah Abdullah, a former foreign minister, was appointed the chief executive officer, a new position that is not provided for by the Constitution. Such circumstances put into question the legitimacy of the government.

Worse, at a time when Afghanistan needs a strong central power for efficient decision-making, the power-sharing arrangement splits the bureaucracy into two camps. This will slow the policy-making process, especially if consensus-building proves difficult.

Some are already predicting a fractured, contested and corrupt government. Recent examples of power-sharing do not inspire confidence: In Kenya and Zimbabwe, such unity governments have led to the stalling of reforms.

Still, there are glimmers of hope for success in the Afghan case, given that the two leaders have worked together as Cabinet ministers in former president Hamid Karzai's government.

Both are competent leaders and technocrats who have worked with the international community and share a moderate approach. If they can put behind them the rancour of the past months to work together, the future won't be dire.

They have their work cut out for them: bridging the rift between their country and the West that grew under Mr Karzai's watch; tackling corruption; healing the many fissures of Afghan society and rebuilding an economy ravaged by war. The international community can help by giving support to the Afghan security forces to prevent the kind of rupture that is happening in Iraq, as well as providing developmental aid to help build capacity.

Much has been accomplished under Mr Karzai, like the improvement of health care and the elevation of the status of women. If all these gains are not to be rolled back and if the Taleban is to be kept outside the door, the power-sharing must work.