Pakistan is unlikely to stop being an obstacle to India-Afghanistan trade. Advantage Iran.
No conversation between Dr Manmohan Singh and Hamid Karzai is complete without a mention of Pakistan’s blockade of full bilateral overland trade between India and Afghanistan. Blocking bilateral trade by refusing overland transit suits several of Pakistan’s objectives. It can thwart India’s attempts to build relations with Afghanistan and the landlocked Central Asian countries, and retain influence over a country that the Pakistani ruling establishment sees as its backyard. And this being Pakistan, almost anything that is perceived to be important to India can be pressed into service over the Kashmir issue. Not only does denying India access to Afghanistan work towards Pakistan’s own foreign policy agenda, it serves the interests of its ally to the north — China, which desires to expand its sphere of influence over Central Asia and the Arabian Sea.
If India had retained control (or its claim to) the entire state of Jammu & Kashmir, it would have had a chance to attempt a land route to Afghanistan, albeit through difficult terrain. But with India foreign policy clearly on a path that seeks to formalise the Line of Control into an international boundary, it is unlikely that India will ever be able to have a overland route to Afghanistan that does not cross Pakistani territory. The only alternative is through Iran. This involves a sea-route between Indian and Iranian ports, followed by overland transit across Iran.
To India, the attractiveness of the Iranian option grows with every Pakistani move at linking transit trade to Kashmir. If the United States desires to prevent this from happening, then it must lean on Pakistan to stop being metaphorical bone in India’s (and Afghanistan’s) kebab.