Bold prediction: Pakistan
I was thinking about Pakistan as well. Maybe if Islamsits rise to power and tensions with India rise. But Iraq would look like a cakewalk since Pakistan has a population multiple times of Iraq.
I'm imagining a scenario where the US botches the withdrawal from Afghanistan, the Taliban rises and begins to increase its control in Pakistan. The Pakistani military flips out but the intelligence services do nothing and even encourage the rise in Islamism as a way of flexing their muscles at India. Eventually there's some government collapse/assassination/coup that leads to a civil war and the US and a bunch of other countries intervene to prevent nuclear proliferation to the Islamists.
