They should send an army to capture land till attock. Afghans with wet dream of Loy Afghanistan are not different from sanghi dreaming for akhand bharat.
Afghanistan has no legal, or historic reason not to accept Durand line as international border. They keep harping the borders Ahmad Shah Abdali had in 17th Century as Afghan borders. But that dude died in 1772 and then in 1799 Sikh Sarkar Khalsa defeated his successors to win the lands currently in Pakistan. Then from 1845 onwards the British won these lands from the sikh and then in 1893 Mortimer Durand negotiated the borders of Afghanistan with Iran , Russia and the lands currently with Pakistan were already not in control of any Afghan Ruler after 1799. Even the British forced Afghan rulers to accept Durand line as International border three times in the three Anglo Afghan wars in 1839 , 1878 and 1919. All three times attempts of winning back some territory by Afghans were crushed.All three times Afghans signed agreements accepting Durand line as International border.
So Afghans lost the lands currently with Pakistan how many times? During the three Sikh wars between 1751 to 1837. Then three times from British in the Anglo Afghan wars from 1839 to 1919. Thats six times.
Pakistan was created in 1947 and Afghans wanted to reverse the history back to 1799 or turn the clock 150 years. That doesn't happen and wont happen.
If for any hypothetical reason Afghanistan does succeed to revoke Durand line as international border, they will have to sort it out with Iran and Russia too. Because the same British guy who defined Afghan border with present day Pakistan, also defined Afghan border with Russia and Iran.
The day Pakistan gets a real leader and not these pathetic excuses, Afghanistan will not only accept the durand line, they will respect it as well. Till that time they can enjoy.
I consider stupidest of stupid people who lay claim to a land because some 200 years ago it was their. Geographical boundaries are a reality, Afghanistan has suffered more because of it and will continue to suffer more if it doesn't recognize it.
Solution: Pakistan should claim the Pashtun areas in Afghanistan and there could be many reasons for this fair claim.
When Afghanistan is not recognizing the Durand line, Pakistan is well within its right to do the same and start claiming the Pashtun areas in Afghanistan. And actually this idea will resonate in the Pashtun belt of both the countries.
Hint: FATA people want a merger with Pakistan and join the mainstream.