A four week U.N. conference to improve compliance with the Nuclear Non-Proliferation Treaty (NPT) ended Friday even without adopting a final document. The failure of the NPT review conference, which took place 70 years after the atomic bombings of Hiroshima and Nagasaki, is highly regrettable, especially in view of the achievements at the previous meeting held in 2010. A 64-point action plan adopted in the 2010 conference said, among other things, that "the nuclear weapons states commit to undertake further efforts to reduce and ultimately eliminate all types of nuclear weapons, deployed and non-deployed, including through unilateral, bilateral, regional and multilateral measures."

This year's conference was held at a time when dark clouds hang over efforts to reduce nuclear arms. Although the United States and Russia signed the New START (Strategic Arms Reduction Treaty) in April 2010 and it came into force in February 2011, the confrontation between the two powers in the Ukraine crisis has prevented them from making progress in efforts to cut nuclear weapons. In March, Russian President Vladimir Putin disclosed on a TV program that Moscow was ready to put its nuclear forces on alert to cope with a possible NATO intervention in the Ukraine crisis a year ago. China is seeking to attain operational capability of submarine-launched ballistic missiles so that its navy will have a "first credible long-range sea-based nuclear deterrent." North Korea claimed in early May that it successfully test-launched an SLBM from a submerged submarine — a development that could eventually pose a serious threat to the U.S.

Held amid these difficult circumstances, the review conference had all the more significance and could have played an important role in pushing for progress in nuclear weapons reduction and nonproliferation. The draft of the final document, which did not see the light of day, included recommendation that the United Nations set up a working group to carry out studies for one year from September on effective steps to achieve cuts in nuclear arms. It also called on nuclear weapons states — the U.S., Russia, Britain, France and China, which are also the veto-wielding permanent members of the U.N. Security Council — to issue regular reports on their efforts to reduce nuclear arms, including the number and types of warheads they possess and their deployment, for reviews by the 2017 and 2019 gatherings to prepare for the next NPT review conference and for the 2020 review conference itself.