- The first sentence in your posting answers itself. The countries mentioned above surely had much longer legacy in nuclear weapon programme. Also they piled up more nuclear weapons during cold-war days.
Things are going to change.
It's no more having more weapons, but precise weapons that would act as the force-multiplier. Environmentalists are also getting powerful and create noise in case of underground tests.
So I think like many advanced countries, India would move to lab testing in the era of super computers, parallel processing, super super fast graphics to fine tune its nuclear arsenal.
With modern technology, one could achieve similar efficiency with less resources.
And since we want to ensure "quick and more" resources now to feed our starved reactors, it's a good idea to open more reactors at this moment to IAEA.
This also helps India create a strategic stock pile of nuclear resources.
I believe TIFR is not under IAEA. [Correct me if I am wrong.]
Think.
The world has allowed you to carry on your military nuclear programme in those 7 reactor (as you mentioneed) acknowledging you as a nuclear power.
We have our self-esteem.
And now we will have resources for our civilian nuclear programme.
