Is the central aim of all Nuclear Ban treaties such as CTBT and NPT - disarmament?What was the need for having CTBT when NPT was already there?

Q. Is the central aim of all Nuclear Ban treaties such as CTBT and NPT - disarmament? I assume its the case because citing the disarmament clause, India hasn't joined either. If not, then please differentiate (chronologically) as to what was the need of having CTBT when NPT was already there.

Disarmament has never been the central theme of both these treaties and that is one of the reasons India has not joined. Others are that they are discriminatory and perpetuates the difference between the haves and have-nots. In the discussions surrounding the CTBT, an important distinction is made between three separate issues: horizontal proliferation, vertical proliferation, and disarmament. Horizontal proliferation refers to the development or spread of existing weapons technology to new or threshold countries such as India, Pakistan, Israel, South Africa or Brazil. Vertical proliferation, on the other hand, refers to the upgrading and further development of more sophisticated weapons by the existing nuclear powers. Disarmament, of course, refers to the dismantling of existing nuclear weapons by the five nuclear weapon states (N5).

The most significant feature of the CTBT text, and of the Nuclear Non-Proliferation Treaty (NPT) is that they both essentially address only the first of these goals - horizontal proliferation. while the CTBT requires all its signatories to stop underground nuclear testing (which would effectively stop horizontal proliferation), it carefully avoids any substantive or enforceable terms on either vertical proliferation or disarmament - which would directly apply only to the existing nuclear powers.

What was the need for having CTBT when NPT was already there?

The argument for introducing CTBT was to even avoid tests by the aspiring countries. One can test even if not to develop weapons. 1974!

Under the NPT, all signatories were categorized as either nuclear weapon states (NWS) or non-nuclear weapon states (NNWS) based on their status at the time. Essentially, the NPT recognized and legitimized the possession of nuclear weapons by all five declared powers - the U.S., Britain, France, Russia and China. It is perhaps not a coincidence that these are also the five permanent members of the Security Council with veto power. All other signatories fell within the NNWS category and agreed thenceforth not to develop or acquire nuclear weapon technology. India, Pakistan and Israel were among the countries that did not accede to the NPT, and were consequently not bound by these restrictions.

But the only commitment the N5 themselves had to make under the NPT - (and this was considered to be the major inducement in 1968 to get the rest of the world to sign away their nuclear ambitions), was to "pursue negotiations" in "good faith" to disarming their own stockpiles. In addition, they were to pursue good faith negotiations to conclude a treaty on complete disarmament.

Incredibly enough, in spite of the various "good faith" assurances provided, the entry into force of the NPT in 1970 actually precipitated a dramatic acceleration of the weapons programs of the N5. In the first ten years after signing the NPT, between 1970 and 1980, not only did the N5 not disarm, but the US (the largest) more than doubled the number of its strategic warheads, the Soviet Union tripled them, while France and China multiplied their arsenals by four times!

Npt deals with proliferation in its entirety. CTBT on physical testing. It carefully avoided computer simulation for enhancement of capabilities.

There is even a fmct which bans transfer of fissile material to stop testing and development. There is even a fmct which bans transfer of fissile material to stop testing and development. So various regimes were imposed by the N5 to perpetuate their primacy.

Sir one question.. Wasn't NPT a fallout of cold war? Soon after Soviet successfully tested the nuclear weapons US started to negotiate deal on NPT to continue its hegemony..as I thought to preserve its hegemonic ambitions only US started putting pressure on all nations including India to abide by NPT and hence the CTBT.. Correct me if my thinking is wrong here sir..

Cold war alone is not the cause for NPT but it was recognized that the cold war deterrent relationship between just the United States and Soviet Union was fragile. Having more nuclear-weapon states would reduce security for all, multiplying the risks of miscalculation, accidents, unauthorized use of weapons, or from escalation in tensions, nuclear conflict.