Some thoughts on the Pakistan factor in the war in Afghanistan (I hope to write a more detailed analysis later). There's long been much debate on the extent to which Pakistani (read ISI/military) policies have fueled, sustained, and strengthened the Taliban insurgency. [THREAD]

There's no denying Pakistan's enabling role. It's provided sanctuary and other support to Taliban leadership-with whom it had been allied long before launch of the US war-for years.
The scholarly literature shows: When insurgencies have cross-border sanctuaries, they never lose.

Many ask: Why didn't USG impose harsher costs on Pak for providing such support for so long? Well, chalk that up to various factors (from "too big to fail" idea to not wanting to jeopardize critical war logistics, eg Pak supply lines-very costly when shut down Nov '11-July '12).

But let's not underplay other key factors driving the Taliban insurgency. Let's start w/US. There were many initial failures: Not trying to reconcile w/Taliban early on, getting diverted by Iraq War, never articulating a strategy after initial (CT) goals achieved early on, etc.

Then there's the Afghan state. The dysfunction/ ineffectiveness of post-Taliban govts helped the Taliban gain footholds, influence, & control across many rural areas-and helped drive recruitment to the Taliban cause. It capitalized on state misgovernance to boost its insurgency.

Pakistani support is a key reason for the Taliban's overall strength, but the Taliban has managed to diversify its sources of financial and military support. It's drawn cash from the drug trade and many other illicit industries. It's received (some) military support from Iran.

Taliban has capitalized on beleaguered Afghan forces to intensify its insurgency since end of NATO combat mission in Dec. '14. It’s seized heavy weaponry from NATO and Afghan security forces. And it is advantaged by the reality of rising civilian casualties caused by ANSF/NATO.

Bottom line? Various factors have contributed to a horrifically deadly war. It's killed ~200,000 people in Afghanistan since Oct '01, including ~120,000 Afghan security forces & civilians (some estimates much higher). Figures could quickly rise post-Sept. https://watson.brown.edu/costsofwar/figures/2021/human-and-budgetary-costs-date-us-war-afghanistan-2001-2021