Russia-US New START Treaty Ends, No Nuclear Limits for the First Time in 50 Years, Threat to Global Security

New Delhi. The last major legal restriction on nuclear weapons between Russia and the United States has ended. Today, February 5, 2026, the New START Treaty (New Strategic Arms Reduction Treaty) expired. Now, for the first time in almost 50 years, there are no binding limits or rules on the strategic nuclear weapons of both countries, such as intercontinental ballistic missiles, submarine-launched missiles, and bombers. This increases the risk of a new nuclear arms race in the world, and experts consider it a serious threat to global security. Let’s understand this in detail.

First of all – What is the New START Treaty?
The New Strategic Arms Reduction Treaty (New START) was a landmark agreement signed in 2010 to prevent a nuclear arms race. It was signed by then-US President Barack Obama and Russian President Dmitry Medvedev in 2010. The treaty came into effect in 2011. Its objective was to limit the deployment of strategic nuclear weapons capable of targeting a country’s major political, military, and industrial centers. Deployed weapons are considered those that are in active service and can be used immediately.

How was the treaty formed? The complete story
Attempts to control nuclear weapons have been ongoing since the Cold War. Since 1969, the US and the Soviet Union (later Russia) have held several rounds of talks.

1970s SALT agreements: Imposed limits on the number of weapons, but did not reduce them.
1991 START I: The first major reduction, during the time of George Bush and Gorbachev. Thousands of weapons were reduced.
1993 START II: Further reductions, but not fully implemented. In 2002, the SORT (Moscow Treaty): Bush and Putin agreed to reduce warheads to 1,700-2,200, but verification was limited.

Then came New START. In 2009, Barack Obama (USA) and Dmitry Medvedev (Russia) began negotiations. It was signed on April 8, 2010, in Prague (Czech Republic). The US Senate ratified it in 2010, and the Russian Parliament in 2011. The treaty finally entered into force on February 5, 2011. Its initial term was only 10 years. However, there was a provision for a one-time extension of 5 years, which Joe Biden utilized in 2021, extending it until 2026.

What happened after 2021?
In 2023, Russia suspended its participation in the treaty, halting inspections, but claimed to continue adhering to the limits. The reason given was US support for Ukraine in the war. Finally, today (February 5, 2026) the treaty expired. Now both countries are free to increase their weapons as much as they want.

Russia says: Now free from nuclear weapons limits
Russia has said it is no longer bound by the New START treaty limiting the number of strategic nuclear weapons with the United States, as the treaty expires on Thursday. This statement has raised serious concerns about global security. The United Nations has called it a “critical moment” for international peace and security.

The Russian Foreign Ministry said on Wednesday that the US had not responded to President Vladimir Putin’s proposal for both countries to continue adhering to the limits on missiles and deployed nuclear warheads under the treaty for 12 months. The ministry said, “We believe that the parties to the New START treaty are no longer bound by any obligations or mutual declarations under it. Our concerns are being deliberately ignored, which is wrong and regrettable.” Potential consequences of the treaty’s expiration
With the treaty’s expiration, both Russia and the United States would be free to increase their missile arsenals and deploy hundreds of additional strategic warheads. However, experts say that doing so would be technically and logistically challenging and would take time. US President Donald Trump had previously indicated that he might consider extending the treaty, but in January he said that a better agreement would be reached if it expired. Trump has also called for China to be included in any future nuclear negotiations.

The Current Balance of Nuclear Weapons
Russia and the United States together possess more than 90 percent of the world’s nuclear weapons stockpile. As of January 2025, Russia had 4,309 and the US had 3,700 nuclear warheads. France and the UK have 290 and 225 warheads respectively, while China is believed to possess approximately 600 nuclear weapons.

Experts’ Warning
Security experts say that the expiration of New START could trigger a new arms race, which would also be influenced by China’s nuclear expansion. According to Matt Korda of the Federation of American Scientists, in the worst-case scenario, both countries could nearly double their deployed nuclear capabilities.

Pope Leo’s Warning
Before the treaty’s expiration, Pope Leo appealed to both countries not to abandon the limits on weapons and to prioritize shared global interests over the politics of fear and mistrust. Meanwhile, UN Secretary-General António Guterres said that for the first time in more than half a century, the world is entering a period where there will be no binding limits on Russia and the United States, the world’s two largest nuclear powers.

He warned that the risk of nuclear weapons use is at its highest in decades and urged both countries to begin negotiations on a new, verifiable, and risk-reducing treaty as soon as possible. Guterres said, “The world is now looking to Russia and the United States to translate their words into action and take immediate steps to strengthen international security.”