The new U.S. nuclear strategy unveiled on Feb. 2 by the administration of President Donald Trump has splashed cold water on the world’s hopes for a future without nuclear weapons.

The strategy pushes back the progress that has been made in nuclear disarmament and could pose a new, serious threat to the safety of the world.

The 2018 Nuclear Posture Review by the Trump administration is a report that lays down guiding principles for U.S. nuclear policy for the next five to 10 years.

The new nuclear policy sharply veers from the course set by the previous administration of President Barack Obama in the 2010 Nuclear Posture Review.

The new strategy has effectively scrapped the Obama administration’s commitment to reduce the role and the number of nuclear arms.

On the contrary, the Trump administration has made clear its intention to expand the roles and capabilities of America’s nuclear arsenal.

The report stresses the security threats posed by Russia, China and North Korea and argues that “global threat conditions have worsened markedly” since the last Nuclear Posture Review in 2010.

But the notion that national security can be maintained only by overwhelming nuclear firepower is hopelessly anachronistic.

The Cold War era, when the United States and the Soviet Union were locked in a dangerous and futile arms race, is already history.

The threat of nuclear arms has become far more complex and diversified and now include those related to international terrorist groups and cyberattacks.

If it keeps maintaining a massive stockpile of ready-to-use nuclear weapons, the United States will contribute to increasing the risks of accidental nuclear war due to human error and theft of nuclear material, exposing the entire world to the danger.

That is why a nonpartisan group of four elder U.S. statesmen, including former Secretary of State Henry Kissinger and former Defense Secretary William Perry, wrote a newspaper opinion piece in 2007 proposing steps toward a world free of nuclear weapons. Their call led to Obama’s efforts to reduce the size and scope of the U.S. arsenal.

The Trump administration should learn from the long history of debate on the issue.

What is particularly worrisome about the report is the administration’s plans to develop “low-yield” nuclear warheads to be mounted on submarine-launched ballistic missiles and cruise missiles.

Thinking that building up smaller nuclear weapons that are easier to use would be more effective in deterring attacks by enemies seems to signal a lack of good sense.

If the border between nuclear and conventional weapons blurs, the likelihood of accidental nuclear war would rise.

The new policy also warns that the United States could use nuclear weapons in response to non-nuclear attacks. Potential scenarios of such nuclear responses apparently include large-scale cyberwarfare. But this thought indicates a dangerous willingness to choose nuclear options.

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT), which the United States has signed, requires nuclear powers to pursue nuclear disarmament.

As a leading nuclear power, the United States should bear an especially heavy responsibility.

By also applying its America First principle to nuclear strategy, the Trump administration is acting in an irresponsible way that could deliver a heavy blow to the international regime to prevent nuclear proliferation.

In his State of the Union address to Congress last month, Trump said, sarcastically, “Perhaps someday in the future there will be a magical moment when the countries of the world will get together to eliminate their nuclear weapons.”

Trump’s apparent inability to imagine the terrifying destruction nuclear arms could wreak and his desire to secure America’s military superiority over others constitute the largest concern for the future of the world.

--The Asahi Shimbun, Feb. 4