LONDON – The nonproliferation regime is in crisis with North Korea’s defiance and Iran’s continuation of its nuclear program despite opposition from the international community. Yet while a lot of discussion is happening about what can be done about these two states, no one seems willing to take on the elephant in the room: China.

Not only has China played a crucial role in the North Korean and Iranian nuclear programs, its nuclear engagement with Pakistan potentially remains the most destabilizing factor in the global management of nuclear weapons technology.

Last month Beijing confirmed its plans to sell a new 1,000-megawatt nuclear reactor to Pakistan in a deal signed in February. This pact was secretly concluded between the China National Nuclear Corp. (CNNC) and the Pakistan Atomic Energy Commission during the visit by Pakistani nuclear industry officials to Beijing on Feb. 15-18. This sale will once again violate China’s commitment to the Nuclear Suppliers Group (NSG) and contravenes China’s promise in 2004 while joining the NSG not to sell additional reactors to Pakistan’s Chashma nuclear facility beyond the two reactors that began operating in 2000 and 2011.

While this issue is likely to come up for discussion at the June meeting of the NSG in Prague, Beijing has already made it clear that nuclear cooperation between China and Pakistan “does not violate relevant principles of the Nuclear Suppliers Group.” This when the CNNC is not merely constructing civilian reactors in Chashm but also developing Pakistan’s nuclear fuel reprocessing capabilities and working to modernize Pakistan’s nuclear arsenal.

At a time when concerns about Pakistan’s nuclear program are causing jitters around the world, China has made its intention clear to go all-out in helping Pakistan’s nuclear development. Yet, with the diplomatic energies focused on Iran and North Korea, there is little discussion about the serious implications of this trend.

China has been bolstering Pakistan’s nuclear capabilities for the past five decades in an attempt to maintain parity between India and Pakistan. Based on their convergent interests vis-a-vis India, China and Pakistan reached a strategic understanding in mid-1950s, a bond that has only strengthened ever since.

Sino-Pakistan ties gained particular momentum in aftermath of the 1962 Sino-Indian war when the two states signed a boundary agreement recognizing Chinese control over portions of the disputed Kashmir territory. Since then, ties have been so strong that former Chinese President Hu Jintao described the relationship as “higher than mountains and deeper than oceans.”

It was Pakistan that, in the early 1970s, enabled China to cultivate its ties with the West and the United States in particular, becoming the conduit for Henry Kissinger’s landmark secret visit to China in 1971 and has been instrumental in bringing China closer to the larger Muslim world.

Over the years China emerged as Pakistan’s largest defense supplier. Military cooperation between the two has deepened with joint projects producing armaments ranging from fighter jets to guided missile frigates. China is a steady source of military hardware for the resource-deficient Pakistani Army. It has not only given technology assistance to Pakistan but also helped Pakistan to set up mass weapons production factories.

But what has been most significant is China’s major role in the development of Pakistan’s nuclear infrastructure, emerging as Pakistan’s benefactor at a time when increasingly stringent export controls in Western countries made it difficult for Pakistan to acquire materials and technology from elsewhere.

The Pakistani nuclear weapons program is essentially an extension of the Chinese one. Despite being a member of the NPT, China has supplied Pakistan with nuclear materials and expertise and has provided critical assistance in the construction of Pakistan’s nuclear facilities. Although China has long denied helping any nation attain a nuclear capability, the father of Pakistan’s nuclear weapons program, Abdul Qadeer Khan, himself has acknowledged the crucial role China has played in his nation’s nuclear weaponization by gifting 50 kg of weapons grade-enriched uranium and tons of uranium hexafluoride for Pakistan’s centrifuges. This may be the only case where a nuclear weapons state has passed on weapons-grade fissile material as well as a bomb design to a nonnuclear weapons state.

India has been the main factor that has influenced China and Pakistan’s policies vis-a-vis each other. Whereas Pakistan wants to gain access to civilian and military resources from China to balance the Indian might in the subcontinent, China, viewing India as potential challenger in the strategic landscape of Asia, views Pakistan as it central instrument to counter Indian power in the region.

The China-Pakistan partnership serves the interests of both by presenting India with a potential two-front theater in the event of war with either country. Not surprisingly, one of the central pillars of Pakistan’s strategic policies for more than four decades has been its steady and ever-growing military relationship with China. And preventing India’s dominance of South Asia by strengthening Pakistan has been a strategic priority for China.

But with India’s ascent in global hierarchy and American attempts to carve out a strong partnership with India, China’s need for Pakistan is only likely to grow. A rising India makes Pakistan all the more important for Chinese strategy for the subcontinent.

It’s highly unlikely that China will give up playing the Pakistan card vis-a-vis India anytime soon. And in this business of great power politics, weakening nuclear nonproliferation will continue to be a second order priority for Beijing.

Harsh V. Pant teaches at King’s College London.