Pakistan's long-term policy of supporting and providing sanctuary to militants in the frontier provinces is coming back to bite it. The allowed places like North Waziristan to become lawless bases for the Taliban and Al-Qaeda, and they are reaping the "reward".
Pakistan's Inter-Services Intelligence has for years supported the Afghan Taliban (in fact, they essentially created it) as they calculated it was vital to their strategic security to control Afghanistan. The Pakistani Army determined that to have any chance (even very small) of prevailing in a war against India, their armoured divisions would need to be able to carry out a defence-in-depth, and to be able to withdraw into the Afghan Pashtun hinterlands, before counterattacking.
This policy of controling an Islamist emirate in Afghanistan would also put at their disposal some tens of thousands of jihadi auxiliaries who would help fight Indian troops. All through the years of the war on Terror, Pakistani armed forces and intelligence accepted billions from the US as payment to fight terror while at the same time providing materiel, safehaven and advice to the Afghan Taliban.
Some years ago, a new Taliban faction called the Pakistani Taliban (or TTP; Tehrek-i-Taliban) formed. In recent years, TTP has been supported by Afghan intelligence to get back at Pakistani for supporting the Afghan Taliban and the Haqqani Network (which fights with the Taliban). All four groups (TTP, Afghan Taliban, Al-Qaeda and Haqqani Network) operated around the same areas in the Pashtun border hinterlands in Pakistan around Waziristan.
Finally in the last couple of years, Pakistan has become serious about clearing out the Waziristan tribal areas of militants and launched an operation called Zarb-e-Azb (swift, cutting blow). They had some successes and also suffered many casualties. TTP also carried out that attack on a school that catered to the children of army officers (https://en.wikipedia.org/wiki/2014_P...chool_massacre
). TTP has become increasingly brazen, and once you attack the Pakistan army's kids you cross a line. I hope, for Pakistan's sake, that they do not backslide. They have to continue clearing out the tribal areas.
The benefit of their clearing these areas is also likely to be that the Afghan government starts to make real progress against the Afghan Taliban. One can hope