> What happens when a nuclear power like India starts to lack food?

Personally I think that actually seems a bit unlikely. Most of India's energy doesn't come from oil and doesn't go to agriculture. It seems plausible that the global economy will be able to overcome the food and fertiliser issues even in the short term, there is a lot of food out there.

I'm expecting the threat to be more complex economic goods like construction, manufactured goods, leisure and general logistics. I don't want to downplay the risk, famine in India is a scary thought, but I don't really see how we'd get there from closing the Strait of Hormuz without a lot of bad luck. The problem is it is going to materially impoverish a number of people and collapse complex supply chains rather than make it hard to get food to them.