Nothing. We can continue to develope nuclear weapons. But for the weapons to be reliable, we will have to Test. No amount of computer simulations can substitute actual tests. We have so far tested some 5 or 6 devices. US and other nuclear powers have except Pakistan have done a large number of tests.
Once we test, the 123 agreement is terminated. NSG - who would supply the fuel, works on consensus and US holds significant influence in this group. If US can not supply uranium under 123 agreement because we tested, the NSG won't supply it either. So the power plants in India would suffer.
This is I believe is extremely unreliable arrangement for such a costly equipments and fuel that we tax payers would pay for.
