Afghanistan has two major ethnic groups; Pashtuns and Farsi speakers. The history of Afghanistan shows that no outsider could succeed to rule them ever. It is better to let them rule their selves but presently the main problem is Al Qaida and Taliban influence there.
Afghanis should rule Afghanistan but not Al Qaida and Taliban.
Hamid Karzai is a controversial president and the majority of Afghan nation will not accept him. The best way will be to let Taliban group leave fighting, join them in talks including all ethnic groups in Afghanistan and make an agreement for a free and fair election to chose members from each and every ethnic group i.e Pashto and Farsi speakers. Pakistan can play an important role in this matter because there is a big number of Pashtuns in Pakistan and they have the same culture as Afghan Pashtuns. Therefore, the elders of Pashtuns can talk to each other, they call it Jirga. These matters can be resolved with talks, not with fighting, as it is proved since more than a decade of heavy fighting without any fruitful result.