Kashif I am not getting a clear idea of what you are saying. About Uranium Enrichment, yes they use it in Nuclear Reactors to create electricity. The trouble with fission (breaking) is it gives a large amount of radioactive isotopes with long half-life. One of these isotopes is Pu-239, or Plutonium. This Plutonium is what is used in nuke bombs. So instead of just disposing of the Pu somewhere, they can put it to some good use, i.e bombs, they gain some respect and hatred, and they don't have to find a way to dispose it somewhere, as they can be stored as bombs. This gives some motivation to make bombs.
About ICBMs, the probability of the US invading India just because they have developed ICBMs is very very remote or none at all. But you never know what might happen !!!