Decipherment of the Indus script would be helpful – if nothing else, it should conclusively settle the non-Aryan/Aryan dispute – but the amount of information this would yield is severely limited.
I should like to see the scientifically conducted large-scale excavation of Ganweriwala, which is potentially a settlement of crucial importance. Was it a city equal in importance and complexity to Mohenjo-daro? Answering this would give a hugely significant insight into the political organisation of the Indus realm. What buildings are on its citadel and what function did they serve? How is the lower town laid out and how are industrial /craft sectors distributed within it? How far does it extend? What is the chronology of its development? How does it relate to the internal communications network? It has the potential to answer many of the questions that cannot be answered by Mohenjo-daro because so much was excavated before excavation techniques were properly developed or by Harappa because the site was so badly damaged in the 19th century. Its situation in the "Saraswati" valley is also of crucial significance: just how important was this region vis-à-vis the Indus realm as a whole?
Peace in the Near East and South Asia and better relations between Afghanistan, Pakistan and India.
Discovery of bilinguals and of many samples of the Indus script in its formative phase, when the pictorial shapes of the signs were less schematized.
Peace between India and Pakistan, commitment to investigating and preserving the past without political interference, and $$$$$$$$$$$ to permit the training and hiring of archaeologists and the carrying out of research. China is advancing so far ahead of India (and Pakistan) in its commitment to the uncovering and preservation of the past that it quite unbelievable.
Pakistanis and Indians tackled two or three sites together and brought out a joint report in 4 or 5 years.
Indians got over their low self-esteem and their imperative to portray “their” old civilization in terms of how they conceive their own society: peacable, the greatest, the oldest, running on caste lines (ugh!) etc.
And then, as mature human beings, we go back and after careful deliberation, ask what new questions we have of Mohenjo-daro and how to tackle these.
Decipherment of the Indus Script!