I found a shocking declassified CIA NSC briefing on the alleged proposal here.
Afghanistan Foreign Minister requests U.S. aid to bring about Afghanistan-Pakistan merger. He claims this is the only way to keep Afghanistan out of increasing Soviet economic envelopment and a matter of life and death for his country. However, Pakistan Prime Minister, Mohammad Ali, who has already been approached, reportedly suspicious of this plan.
The document goes on about talks in Pakistani-Afghan circles on even the possibility of a confederation if not a full merger. It also claims that the Agha Khan was using his influence on Pakistan to make it happen. It also correctly assess that such negotiations were unlikely to yield any results due to internal complications (Economic differences, Pashtunistan controversy) and expected foreign opposition from Soviet Union and India. One thing is clear however that Afghan foreign ministry had already proposed it and was rebuffed quietly by their Pakistani counterparts, which is why they sought American aid in bringing the Pakistanis to the table.
I can understand why the Pakistani PM Mohammad Ali Bogra would be skeptical of any such Afghan proposals due to Afghan-instigated (Quoting CIA here) Pashtunistan controversy, Afghan refusal to acknowledge the border between the two states, Afghan close ties with Pakistan's arch rival India, Afghan-Pakistan border skirmishes and Afghan support for Faqir Ippi rebellion. But the proposal, if accepted, could also have meant an entirely alternate world in which, potentially,:
- There would be no Soviet Invasion of Afghanistan
- No consequent creation of Mujahideen and radicalisation of the region.
- No American support for the notorious dictator Zia ul Haq.
- No rise of terrorist organisations such as Al-Qaeda, Daesh, Taliban etc and therefore no 9/11 or war on terror.
- Soviet Union may have survived and the World wouldn't have become uni-polar.
That's why it intrigues me. But I can't find the exact details of the proposal. Was it just an abstract idea? Or were there at least some details attached to the proposal e.g. hypothetically the Afghan King becoming the Head of State for the United Afpakistan and Pakistani government assuming all other roles or Afghanistan retaining most of internal autonomy but delegating Defence and Foreign affairs to Pakistan.