DW: To what extent North Korea owes its nuclear technology to Pakistan?

Pervez Hoodbhoy: Pakistan did transfer centrifuge technology to North Korea. It did not, however, directly contribute to the program because North Korean nuclear program is essentially based on the extraction of plutonium rather than the uranium centrifugation process.

When did Pakistan's "nuclear transfer" to North Korea begin, and when did it end?

It ended in 2003 when Pakistani scientist A Q Khan was caught in the transfer of nuclear technology and subsequently all nuclear transfer came to an end. It is unclear when it began, but it is possible that it started shortly after former Prime Minister Benazir Bhutto came to power in 1989, so in the years after that it must have begun at some point.

Read more: Why Pakistan's nuclear obsession is reason for concern

Pervez Hoodbhoy: 'In return for the centrifuge that Pakistan supplied to North Korea, it received so-called Dudong missiles'

Was Pakistani scientist A Q Khan the only person responsible for nuclear proliferation to Pyongyang?

It is very hard to believe that A Q Khan single-handedly transferred all technology from Pakistan to North Korea, Libya and Iran as it was a high-security installation in Pakistan and guarded with very fearsome amount of policing and military intelligence surrounding it. Moreover, the centrifuge weighs half a ton each and it is not possible that these could have been smuggled out in a match box, so certainly there was complicity at a very high level.

But some military generals in Pakistan deny helping out Pyongyang because North Korean nuclear technology is a plutonium-based one unlike Pakistan's.

I think that it is true the North Korean nuclear weapons are plutonium-based and this plutonium bomb is not the same as the uranium bomb. Pakistan did supply centrifuges to Pyongyang, but the relation between the North Korean nuclear program and Pakistan is not direct.

What did Pakistan get in return for "helping" Pyongyang?

In return for the centrifuge that Pakistan supplied to North Korea, it received so-called Dudong missiles. These are liquid-fueled missiles, which were taken over by the A Q Khan laboratory and were renamed "Ghouri" missiles. I think they are part of Pakistan's missile arsenal. These are not as effective as solid-fuel missiles, which do not need much preparation time.

So, certainly there was a quid pro quo. I think both North Korea and Pakistan benefited from this exchange, but not majorly.

Does the A Q Khan "nuclear network" still exist?

It is difficult to say that such network exists now. Pakistan's nuclear program is now under observation and it will be very difficult to smuggle nuclear technology out of the country.

Should the international community accept North Korea as a nuclear power the way it accepted Pakistan?

It is now a fact that North Korea has had six successful nuclear tests, and the last one probably that of a hydrogen bomb. This certainly exceeds what Pakistan has achieved and is on par with India's nuclear program.

There is no doubt that a nuclear North Korea is now reality, so the country should be put in the same category as India and Pakistan.

Read more: Hydrogen vs atomic bomb: What's the difference?

What measures should the international community take to counter the threat posed by "rogue states" with nuclear capabilities?

The notion of rogue state is something that has been manufactured by those who already possess nuclear weapons. The United States has used this term time and again in relation to Iran and North Korea, and earlier Iraq as well. The term has no legitimacy because the US itself has used nuclear weapons - once in Hiroshima and once in Nagasaki. Moreover, we have seen that the US actions have not been conducive to world peace. Being a superpower does not give the US a license to label other states around the world as "rogue."

- North Korea: UN Security Council approves new sanctions

- South Korea to bring back US tactical nuclear missiles?

Watch video 03:47 Share 'Hysteria' on the Korean peninsula? Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/2jOnu 'Hysteria' on the Korean peninsula?

Is the Nuclear Non-proliferation Treaty (NPT) still effective and relevant?

The NPT was useful at one point because it did help slowing down the nuclear proliferation. The more countries with nuclear weapons, the more dangerous the world becomes.

But the NPT now has probably outlived its utility. The fact is that nuclear states have not agreed to Article 6 of the NPT and have not moved towards denuclearization. On the contrary, they have created better and more effective nuclear weapons. We therefore need a new and comprehensive treaty.

Dr. Pervez Hoodbhoy is a Pakistani nuclear physicist, mathematician and activist who serves as distinguished professor at the Forman Christian College. His work focuses on Quantum field theory, particle phenomenology, and supersymmetry in the area of Particle physics. Hoodbhoy is also a prominent social and political activist who works for the promotion of freedom of speech, secularism and education in Pakistan.

The interview was conducted by Sattar Khan, DW's Islamabad correspondent.