EDITORIAL: U.S. nuke strategy shift

We welcome U.S. President Barack Obama's latest decision to revise his nation's nuclear strategy.

In an interview Monday with The New York Times, Obama said the United States will not use nuclear weapons against non-nuclear states that comply with the Nuclear Nonproliferation Treaty (NPT).

He also stated the United States, in principle, will not retaliate with nuclear weapons even if it is attacked with biological or chemical weapons as well as conventional weapons or comes under cyberattack.

This reduction in the role of nuclear weapons represents one of the most significant changes under the new U.S. nuclear strategy. (Washington released the Nuclear Posture Review on Tuesday.)

The term "nuclear umbrella" refers to deterrence provided by nuclear powers to guarantee protection of their non-nuclear allies. One could then use the term "non-nuclear umbrella" to denote a nuclear state's guarantee not to use its nuclear weapons against non-nuclear states. This is a novel approach to security policy.

The United States had previously placed nuclear states and their allies together outside the non-nuclear umbrella. But under Obama's new strategy, more than 180 non-nuclear signatories to the NPT will come under the non-nuclear umbrella.

The expansion of this umbrella should make the benefits of faithful observation of the NPT more obvious to each signatory. And this, in turn, should help inculcate the thinking that going nuclear-free is definitely the safer option.

Obama's major challenge ahead is how to win the other nuclear states over to his camp and make the non-nuclear umbrella a global security standard.

Russia's basic policy is not to refrain from using nuclear weapons, even against non-nuclear states--it is a hard-core stance, which may be explained by the fact that Russia is inferior to North Atlantic Treaty Organization allies in conventional weapons capabilities.

The most desirable development would be for NATO members to fall in step with Obama's new strategy. Once Britain and France throw their support behind the policy, NATO ought to proceed with more comprehensive disarmament and security discussions and urge Russia to open its own non-nuclear umbrella.

China has repeatedly asserted its position against making a preemptive nuclear strike. If Beijing really means that, it should support Obama and engage in active diplomacy to expand the non-nuclear umbrella.

Chinese President Hu Jintao will attend the two-day summit meeting on nuclear safety that begins Monday in Washington, D.C. The summit's main theme will be prevention of nuclear terrorism, but we suggest that Hu and Obama get together to discuss the prospects of policy of ending nuclear attacks against non-nuclear states.

In reviewing its nuclear strategy, the Obama administration considered spelling out that the "sole role" of nuclear weapons is to deter nuclear attacks. But the wording was left out, mainly because of the Defense Department's argument that restricting the role of nuclear weapons to such an extent would debilitate the U.S. power of deterrence against non-nuclear threat by North Korea and Iran.

The International Commission on Nuclear Nonproliferation and Disarmament, which is a joint initiative of Japan and Australia, proposed in December that all nuclear states declare by 2012, or as soon as possible after 2012, that the sole purpose of the nuclear weapons they possess is to deter nuclear attacks by other nuclear powers.

Obama's new strategy embodies a historic step forward, and we cannot let it falter. To further reduce the role of nuclear weapons and advance nuclear disarmament, Japan must bolster its diplomatic efforts to urge the world's nuclear states to each make a "sole purpose" declaration.

--The Asahi Shimbun, April 7