With development of nuclear weapons and more efficient ways of delivering nuclear payloads, strict regulation was required. As the Cold War geared up, the arms race was in full swing. Eventually attempts to contain it resulted in the Treaty on the Non-Proliferation of Nuclear Weapons. This Treaty is the “only binding commitment in a multilateral treaty to the goal of disarmament by the nuclear-weapon States”, as the UN notes. It entered into force in 1970 and in 1995 it was extended indefinitely.
But, of course, a document is only as good as it is implemented. One thing is certain – no nuclear weapons were used in warfare since the Hiroshima and Nagasaki bombings. However, that doesn’t mean the non-proliferation efforts were a complete success. In 2012, UN Secretary-General BAN Ki-moon admitted in an opinion piece:
National budget priorities still tend to reflect the old paradigms. Massive military spending and new investments in modernizing nuclear weapons have left the world over-armed — and peace under-funded. Last year, global military spending reportedly exceeded $1.7 trillion – more than $4.6 billion a day, which alone is almost twice the UN's budget for an entire year. This largesse includes billions more for modernizing nuclear arsenals decades into the future.
There was at least one major success of the UN — the Cuban Missile Crisis. The Cold War reached its apex in October of 1962, when the world was on the brink of an all-out nuclear war. The crisis itself is a complicated matter for a separate discussion, but what most people don’t realize is that it was averted mostly thanks to the United Nations. Walter Dor, professor at the Royal Military College of Canada and Chair of the Canadian Pugwash Group wrote:
[The] favourable result was not merely due to US military threats or even the Soviet leader’s common sense. There is another story hidden behind the nuclear showdown that transcends the contest of wills and that remains relevant today. A quiet unassuming UN Secretary-General, U Thant, actively mediated and helped resolve this nuclear confrontation. At the request of much of the UN member states he was able to push the leaders to step back from the brink to give diplomacy a change.
But it doesn’t always work. Five permanent members of the United Nations Security Council are allowed to have nuclear weapons and are officially recognized as NPT-designated nuclear weapon states. Meanwhile, four UN member states have never joined the NPT: India, Israel, Pakistan and South Sudan – two of those, India and Pakistan, have conducted nuclear weapon tests. Israel is suspected of possessing nuclear weapons. And North Korea withdrew from the NPT in 2003 and supposedly conducted nuclear weapons tests.
In the case of North Korea, the matter was referred to the UN Security Council, and international pressure was applied to the country. Whether it’s effective enough, and whether the drawn-out talks on the Iranian issue can be called a success or a failure is unclear at this time.