The world’s five recognized nuclear powers took a step in the right direction when they recently pledged to avoid nuclear war at all costs. But that promise is meaningless unless it is honored with specific and vigorous actions.

The United States, Russia, Britain, France and China issued an unusual joint statement affirming their commitment to avoiding nuclear war among them and confirming the importance of nuclear disarmament and nonproliferation.

“We affirm that a nuclear war cannot be won and must never be fought,” the English-language version of the statement said, quoting a passage from a joint declaration by Ronald Reagan and Mikhail Gorbachev at a 1985 summit held during the Cold War era in Geneva. The leaders of the five nations should also emulate what Reagan and Gorbachev achieved and take specific steps toward reducing their nuclear arsenals.

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) allows the five nations to maintain nuclear arms but also requires them to engage in negotiations in good faith to scale back their nuclear arsenals.

In recent years, however, a nuclear arms race has developed among the leading military powers driven by efforts to develop new weapons technologies. There have even been moves to lower the bar on the use of nuclear arms.

The statement says nuclear weapons should only “serve defensive purposes.” But the reality is that these countries have been responsible for planting seeds of conflict.

China has been trying to change by force the status quo in the South China Sea and other areas. Russia is intimidating its neighbor by deploying tens of thousands of troops near the border.

Britain is moving to enhance its nuclear capabilities in response to threats posed by Russia and China.

The five nuclear-weapons states made a clear promise to eliminate nuclear weapons during the NPT review conference in 2000. But their latest statement made no mention of this fact.

No matter how strongly they may pledge not to engage in war, unexpected and accidental situations, such as armed clashes due to misunderstandings of what is occurring, could develop amid heightened military tensions. The only way to ensure there will be no nuclear war catastrophe is to eliminate nuclear weapons completely.

The 10th NPT Review Conference, which was scheduled to start Jan. 4 in New York, has been postponed due to the COVID-19 pandemic. Whenever it is eventually held, it will be vital to make the five leading nuclear weapons states firmly commit to matching their words with action.

There are also three nuclear powers that are not parties to the NPT: India, Pakistan and Israel. And then there is North Korea, which has declared its withdrawal from the treaty.

The global nuclear nonproliferation regime, which has been a key factor for national security since the Cold War era, is now facing serious challenges to its relevance.

A sense of crisis about this situation drove the international movement led by non-nuclear powers to establish the treaty on the prohibition of nuclear weapons. The treaty entered into force last year after the required number of countries ratified it. The first meeting of the states that are parties to the treaty is slated to be held in March.

The United States, Britain and France are often at loggerheads with China and Russia over security issues at the U.N. Security Council and other international venues to discuss such topics. In a rare show of unity, the five countries issued a statement stressing the importance of nuclear arms reduction, apparently due to growing pressure from international calls for the elimination of nuclear arms.

This indicates the nuclear ban treaty is already making its effects felt.

But Prime Minister Fumio Kishida remains reluctant to get Japan involved in the process. The NPT and the nuclear ban treaty are two crucial tools to push the world toward a future without nuclear weapons.

As the only nation to have experienced wartime nuclear devastation, Japan should serve as a “bridge” between the two camps by taking part in discussions over both treaties and contributing to building a system in which they complement each other.

--The Asahi Shimbun, Jan. 6