What is the truth behind CTBT?

We all are worried about the nuclear ambitions(?) of Iran, North Korea and other states. During the recent UN General Assembly session, the voice supporting CTBT was raised again. Out of curiosity, I started looking for CTBT and why India is not signing it. So, here is what I think about it:

The Comprehensive Test Ban Treaty (CTBT), which opened for signature in 1996, is intended to prohibit all nuclear weapon test explosions. The CTBT has achieved near universal adherence, however, Article XIV of the Treaty requires ratification by 44 named states, before the Treaty can enter into force.

Of these 44 states, three - India, Pakistan, and North Korea - have not signed the Treaty. A further six states - China, Egypt, Indonesia, Iran,Israel, and the United States - have signed but not ratified the Treaty.

Ref: http://www.acronym.org.uk/ctbt/index.htm

So, its only a ban on the test. And who would be interested in conducting nuclear tests? Nations that do not have these capabilities yet, namely. Developed nations such as US of A, Russia, UK, France etc. already have nuclear weapons in their arsenal. So, is it really judicious to stop other nations that do not have these capabilities in developing it? Nuclear arsenal of the developed nations clearly gives them advantage over other countries and hence they can use their influence to get things done as per their economic / political interest.

Till date, the only use of nuclear bomb is US of A. Has US of A already destroyed its nuclear arsenal? Has Russia, who is arguably the largest nuclear power, destroyed its arsenal?

So, countries like US of A, Russia, UK (member's of UNSC) who have nuclear arsenal does not want other countries to acquire nuclear technology by conducting tests. They will seat on their nuclear pile and dictate others that it is not in the interest of the world to have this technology.

Can these nations first disarm themselves and set an example? I guess no. I am against usage of nuclear weapons, but Geo-political scenario in south-east Asia demand India to posses nuclear capability for its defense (and not offence). I agree that the more nuclear weapons we have in this world, the more dangerous position we will be as a human being. But is CTBT the right way?

The right way probably is to punish people who are involved in nuclear proliferation. Does UNSC have guts to prosecute A.Q. Khan and his network? Can they force Pakistan to handover A.Q. Khan? Have they even had a chance to talk to him since he has been confined to his house in 2003?

I argue that developed nations have double standards.

The better solution, I can think of, is to "pound militarily" whichever country that uses nuclear weapons / hosts so called "non-state" actors that uses nuclear weapons.