Democracy in Afghanistan

It was reported this morning that there were significant irregularities in the recent presidential elections in Afghanistan. Voting fraud and intimidation were evident in abundance. Why is it taking so long for democracy and free and fair elections to take hold in Afghanistan? Afghanistan has already had eight years. Just because it took us here in the U.S. over two hundred years to work out the kinks and irregularities in our electoral system; even with a head start, doesn't mean that Afghanistan shouldn't be able to sort it out in eight.