I'm not sure what world you live when you accuse Afghans of supporting terrorism whilst your defence minister openly admitted on Live Tv that Pakistan has suppprted militant terror groups for 40 years. Pakistan has groups like Lashkar e Taiba, Sipah e Sahaba, jaish e mohammad, lashkar e jhangavi etc etc.
I'm not sure if you've heard of the saying "One man's terrorist is another man's freedom fighter". What India calls terrorists, Pakistan calls freedom fighters and vice versa.
Pakistan supported the jihadi groups because it was in Pakistan's interest to stall USSR in Afghanistan as Pakistan would have been next on the list. Russia's aim was to access warm waters of Indian ocean and get close to energy corridors of persian Gulf. Another reason was that Americans wanted revenge for Vietnam and Pakistan being in the American camp since 50s made Pakistan an ideal launchig pad for Afghan Jihad. In a strange way Pakistan hosting CIA operatives in badabir airbase near Peshawar since 1956 to spy on USSR also forced USSR to get involved in Afghanistan and make sure Americans don't get a foothold. It was a continuation of the great game between Russia and Britain.
If Pakistan was so sincere in helping Afghanistan fight foreign invaders, it wouldn't have let America/Nato use Pakistan as a transit route for over 20 years to continue the war in Afghanistan.
Afghans should have amso let the Russians use Afghanistan as a launching pad to attack Pakistan but our people fought in their own land rather than letting the fight happen in Pakistan.
Pakistan did what it did to look after it's own interests without any regard for what happens to Afghanistan and Acghanistan reserves the same right to look after it's own interests regardless of what happens to Pakistan. That's the harsh reality and lessons learnt during the last 50 years