Complex sentence: The attack took place as the CIA expanded its role in the Afghanistan War, increasing paramilitary operations, including drone attacks in Pakistan, and building a number of bases in the southern and eastern provinces of Afghanistan.
Split into simpler sentences: The attack took place as the CIA expanded its role in the Afghanistan War, increasing paramilitary operations, including drone attacks in Pakistan. To accomplish this, the CIA had built a number of bases in the southern and eastern provinces of Afghanistan.