Think of new US Afghan policy in terms of desperate response for US failures and fading power. Bigger picture (target) for US policy makers, 3 generals who are holding US power (WH Chief of staff, defense secretary and NSA), are to thwart OBR and Eurasian integration. To do that CPEC is the major component of US target. Given regional alignments shaping up from Mediterranean to Pakistan (Syria, Iraq, Iran, Turkey, Russia, Pakistan and China), US lost and losing its almost century old power broker position. US does not have any way to pursue its interventionist policy in Central Asian region other than foothold its has in Afghanistan.Consider these backdrops:
1) US lost in Afghanistan and no possible way to influence reality on ground.
2) It is Pakistan which has dominant influence in Afghanistan and access route to Afghanistan.
3) US has no economic or meaningful influence in Pakisitan other than some pockets of influence in Pakistani establishment.
So, US policy announcement is just effort to browbeat Pakistan with media, empty threats and rhetoric. Pakistan has full capability to counter such rhetoric if Pakistani establishment can come out of lingering US nostalgia.
On regional sphere :
3) There is already an alliance shaping up with Turkey, Iran Russia, Syria and Iraq. That means doors in ME are shutting on US (Saudi based) policy and influence.
4) Pakistan, China and Russia already in sync on future of Afghanistan and oppose US proxy of ISIS.
5) Iran is already on so much odd with US that its leadership threaten to withdraw from nuclear treaty.
That gives plenty of ways for Pakistan to firm up existing understanding with China, Russia and pull Iran into the fold.
Only thing US can do is act as an spoiler using its ISIS and indian proxy. But combined Pakistan, China, Russia + Iran weight can easily rout US out of the Afghanistan. Russian and Iranian has shown how to deal with and US and its proxy terrorists in Syria. And Kim Jong UN is showing how US threats could be dealt with. Pakistan has far greater position and backing to corner US on its own game; starting with stopping all logistic supply route.