A decision by the Nuclear Suppliers Group (NSG) on June 23-24 – as to whether to include India as a member – may be overshadowed in international media by other expected developments. These include the results of Britain’s referendum on staying in the European Union, an unprecedented US presidential election campaign, and the imminent ruling by an international court of arbitration in The Hague between China and the Philippines on the South China Sea.

But the NSG meeting is no less important, for the potential implications it could have for relations between India and China. A decision, particularly if it were not to go in India’s favour, would have reverberations for Asian security, climate change and global governance.

NSG is a 48-country cartel initially formed in 1974 after India’s first nuclear test, to control the flow of nuclear technology and supplies. A consensus decision at its next plenary meeting in Seoul, South Korea, to include India as a member would help India’s integration into the global nuclear order, completing its transition from an alleged rule-breaker to a formal rule-maker. India’s ability to export civilian nuclear materials and technology could also help lower the costs of nuclear energy and could boost the sector in energy-starved India.

By extension, it would facilitate India’s ability to deliver upon its commitment, made before the 2015 Paris climate summit, to source 40% of its electricity from non-fossil fuel sources by 2030. For the past several years India has been working to align its nuclear and dual-use export controls with NSG guidelines, to make a strong case for membership.

Prime Minister Narendra Modi has in recent months become personally invested in the matter, visiting Mexico and Switzerland to secure those countries’ support and personally reaching out to leaders of other countries who have expressed hesitation. Support for India’s NSG membership has consequently become a litmus test of relations with India.

Resistance to India’s inclusion has emanated from some predictable sources. Several smaller countries in Europe and elsewhere had earlier expressed concerns, echoed by non-proliferation groups in the US and elsewhere who believe that India’s entry somehow undermines the nuclear Non-Proliferation Treaty (NPT) and encourages Pakistan’s rapidly-growing nuclear arsenal. These are hollow arguments. NSG and NPT are distinct arrangements, while Pakistan’s growing nuclear arsenal is increasingly an insurance against US intervention.

However, the primary resistance to India’s inclusion comes from China. Beijing’s main argument is that India is a non-signatory of NPT, but it conveniently overlooks the fact that France was admitted as an NSG member before it joined NPT. India believes NPT is fundamentally unfair, permanently legitimising the nuclear weapons of certain countries, including China, while denying India for no reason other than its belated development of nuclear weapons.

China’s resistance to India’s membership is ultimately political, intended to constrain India’s rise as a global power. India is often described as a swing power in the evolving international system.

While deepening its strategic partnership with the US as a fellow democracy and status quo power, New Delhi has found common cause with Beijing in many areas. China is India’s largest trade partner in goods, and is an increasingly important source of investment. India and China also cooperate in various international forums, including on matters of national sovereignty and on increasing representation for the emerging markets in global governance.

China’s decision to accept or deny India’s membership in the NSG is therefore crucial. Its marshalling resistance in the face of overwhelming support for India would severely set back its relations with India, with possible consequences for bilateral goodwill, cooperation on climate change and multilateral groupings such as Brics.

China’s actions would stand in stark contrast to the US, which has actively lobbied for India’s inclusion in NSG. This would have reverberations for India’s international orientation. The future of Asian geopolitics could well be determined later this year in The Hague. But just as easily, it could be shaped by a decision made at Seoul in a couple of days.