Many observers have commented on what appears to be new strategies adopted by the Taliban in 2014. The first is the massing of large numbers of insurgents to attack formations and bases of the Afghan National Army (ANA) and the Afghan National Police (ANP) located in small detachments in some remote district centers. The second new strategy is the targeting of intelligence officials of the National Directorate of Security (NDS).
The first, massing of large forces, is now possible because the ISAF airplanes (and choppers) that provide close air support (CAS) have dwindled and the lack of ISAF JTACs on the ground to direct the airstrikes. The Afghan Air Force (AAF) is far from able to provide close air support. The AAF has just a few aged Mi-35 HIND Attack Helicopters (export model of the Mi-24) and will not receive the Super Tucano until 2016. Another limiting factor is the minimal amount of Afghan Tactical Air Controllers (ATAC). In the past the insurgents would be hammered by CAS if they massed or attacked installations; however, that threat is no longer there.
Everyone knows that (well, . . . almost everyone) intelligence drives operations in a counterinsurgency. The ISAF ISR structure has, like its CAS capability, dwindled. The brigades that used to share the battlespace with the ANSF have gone home, and what little intelligence assets remain behind sometimes have trouble sharing information with their Afghan counterparts. The best Intel that the Afghans can provide is HUMINT - and that means the NDS. So the Taliban targeting the NDS is a good strategy (for them) as it diminishes the most important Intel asset that the ANSF can count on.
Read more in "Taliban Devise New Strategy in Afghanistan: Territorial Control and War on Afghan Intelligence Headquarters", The Jamestown Foundation, September 26, 2014.