The End of the Nuclear Arms Control Era

The New Strategic Arms Reduction Treaty (New START), the only remaining nuclear weapons limitation agreement between the United States and Russia, expires on February 5. Once this treaty lapses, both nations will be able to expand their nuclear arsenals without limits on the number of nuclear warheads, intercontinental ballistic missiles (ICBMs), or strategic bombers.

Tilman Ruff, founding chair of the International Campaign to Abolish Nuclear Weapons (ICAN), warned that "in terms of nuclear risk and disarmament, this is a potentially very bleak situation," adding that "we are entering an unprecedented era where the world's two largest nuclear powers are operating without treaty constraints."

Ahead of the treaty's expiration, Russia announced the successful test launch of its Poseidon super-heavy nuclear torpedo. Russian President Vladimir Putin expressed confidence last October, stating "there has never been anything like this before." According to Russian media reports, 30 Poseidon torpedoes will be deployed on four submarines and are scheduled to become operational early next year.

Poseidon: A New Dimension of Nuclear Threat

Poseidon represents a weapon system on an entirely different level from existing nuclear capabilities. Its key specifications are as follows:

This weapon is reportedly capable of neutralizing aircraft carrier strike groups in a single blow or covering coastal cities with radioactive tsunamis. While some military analysts believe Russia's claims may be exaggerated, if even a portion of the advertised capabilities are realized, it is expected to be a game-changer that could reshape the nuclear deterrence landscape.

Professor Stephan Fruehling of the Strategic and Defence Studies Centre at the Australian National University (ANU) assessed that "we are clearly entering an era again where nuclear weapons play a much more central role in national survival."

From Disarmament to Arms Race: Historical Context

Efforts to limit nuclear weapons began with the dawn of the nuclear age. Robert Oppenheimer, who directed the U.S. nuclear development program during World War II, was among the first to advocate for international agreements to avoid an arms race immediately after the war.

During the Cold War, the United States and Soviet Union concluded several nuclear arms reduction treaties. Starting with the Strategic Arms Limitation Treaty (SALT) in 1972, through START I in 1991, and New START in 2010, both nations gradually reduced their nuclear arsenals.

New START limited each country to 1,550 deployed strategic nuclear warheads and a combined total of 700 deployed ICBMs, submarine-launched ballistic missiles (SLBMs), and strategic bombers. Thanks to this treaty, nuclear warheads, which numbered in the tens of thousands during the Cold War, were significantly reduced.

However, after February 5, 2026, these limitations will completely disappear.

China's Rise and the Tripolar Nuclear Order

Complicating the situation further is China's rapid nuclear weapons buildup. China has now emerged as the world's third-largest nuclear power, far surpassing the levels of India, Pakistan, the United Kingdom, and France (whose combined nuclear warheads total approximately 1,000).

U.S. President Donald Trump has previously expressed willingness to attempt trilateral nuclear arms reduction negotiations including China. However, China has shown a passive attitude toward such proposals and has not disclosed its nuclear weapons count.

New Risks of Nuclear Proliferation

Countries without nuclear weapons also represent potential threat factors. Dozens of nations operating civilian nuclear power plants theoretically possess the capability to develop nuclear weapons. North Korea flaunts its nuclear capabilities, Israel maintains ambiguity about its arsenal, and suspicions about Iran's nuclear development persist.

Following New START's expiration, the United States and Russia are expected to produce new nuclear warheads and redeploy existing stockpiled warheads. Arms control experts worry that this could provide other nations with justification for developing or expanding their nuclear weapons programs.

[Analysis] An Era Without Treaties: What Lies Ahead

The expiration of New START is not merely the end of one treaty but signifies the collapse of the nuclear age arms control regime. The following scenarios are likely to unfold:

First, U.S.-Russia nuclear rearmament. Both nations, freed from treaty constraints, will accelerate the development and deployment of new nuclear warheads. New weapon systems like Russia's Poseidon will be fully deployed, and the United States will likely develop countermeasures.

Second, difficulties in trilateral negotiations including China. The U.S.-Russia-China trilateral negotiations proposed by President Trump have low feasibility. China has little incentive to engage in negotiations that would disadvantage it given its significantly smaller nuclear arsenal compared to the U.S. and Russia.

Third, increased nuclear proliferation risks. As major powers expand their nuclear arsenals, pressure for nuclear development among potential nuclear-capable states such as South Korea, Japan, and Saudi Arabia could intensify. This could shake the foundations of the Non-Proliferation Treaty (NPT) regime.

Fourth, heightened risk of accidental nuclear war. When the treaty was in effect, mutual verification mechanisms and transparency guarantees were operational, but now even those are gone. The possibility of nuclear war breaking out due to miscalculation and misunderstanding will inevitably increase.

The "nuclear arms race" that Oppenheimer warned about 80 years ago faces the crisis of reemerging in the 21st century. Humanity is once again returning to an era where nuclear weapons become a core element of national survival.