New START facts for kids

Quick facts for kids
New START / СНВ-III

Treaty Between the United States of America and the Russian Federation on Measures for the Further Reduction and Limitation of Strategic Offensive Arms
Presidents Obama and Medvedev shown after signing the Prague Treaty
Type	Strategic nuclear disarmament
Drafted	19 May – 9 November 2009
Signed	8 April 2010 (2010-04-08)
Location	Prague, Czech Republic
Effective	5 February 2011
Condition	Ratification of both parties
Expiration	5 February 2026
Parties	•  United States •  Russia
Languages	English, Russian

The New START treaty was an important agreement between the United States and Russia. Its full name was "Measures for the Further Reduction and Limitation of Strategic Offensive Arms." This treaty aimed to reduce the number of powerful nuclear weapons that both countries had. It was signed on April 8, 2010, in Prague, and became active on February 5, 2011.

New START replaced an older agreement called the Treaty of Moscow (SORT). It also followed the START I treaty, which had ended in 2009. The main goal of New START was to make the world safer by limiting the most dangerous weapons.

The treaty called for a big reduction in the number of strategic nuclear missile launchers. It also set up a new system for checking and verifying these reductions. On February 21, 2023, Russia announced it was suspending its involvement. However, Russia stated it would still follow the limits set by the treaty. The New START treaty officially expired on February 5, 2026.

Understanding the New START Treaty

This treaty set limits on the number of strategic nuclear warheads each country could have ready to use. Each side was limited to 1,550 deployed warheads. This was a much lower number than in previous agreements. A "warhead" is the part of a missile that carries the nuclear explosive.

The treaty also limited the number of vehicles that could deliver these weapons. These included intercontinental ballistic missile (ICBM) launchers, submarine-launched ballistic missile (SLBM) launchers, and heavy bombers. Each country could have up to 800 deployed and non-deployed launchers and bombers. The number of *deployed* (ready-to-use) ICBMs, SLBMs, and heavy bombers was limited to 700.

To make sure both sides followed the rules, the treaty allowed for inspections. Each year, 18 on-site inspections could happen. These checks helped verify the numbers and locations of weapons. Countries had seven years from when the treaty started to meet these limits. The treaty was designed to last for ten years. It also had an option to be extended for up to five more years if both countries agreed.

How the Treaty Came to Be

Drafting and Signing the Agreement

The idea for New START came after the START I treaty. Leaders from the United States and Russia began discussing a new agreement in April 2009. These talks happened after a meeting between Presidents Barack Obama and Dmitry Medvedev in London. Many rounds of talks took place in cities like Geneva and Moscow.

On July 6, 2009, the two presidents announced they had agreed on a plan. This plan aimed to reduce nuclear warheads to between 1,500 and 1,675 units. It also sought to limit the weapons that deliver them to between 500 and 1,100 units. Presidents Obama and Medvedev officially signed the New START treaty on April 8, 2010, in Prague.

Approving the Treaty

For the treaty to become law, both countries had to approve it. This process is called ratification. In the United States, the U.S. Senate had to vote in favor. In Russia, the State Duma and the Federation Council had to approve it.

The U.S. Senate gave its approval on December 22, 2010. President Obama then signed the final documents on February 2, 2011. In Russia, the State Duma approved the treaty in January 2011. The Federation Council then approved it, and President Medvedev signed the ratification resolution on January 28, 2011. The treaty officially became active on February 5, 2011, when both countries exchanged their approval documents.

Key Treaty Activities

The New START treaty included several important steps to ensure it worked.

• Information Exchange: Soon after the treaty started, both countries shared details about their inspection airplanes and teams. They also exchanged databases with information on their weapon systems.
• Inspections Begin: Within 60 days, inspections could start. These checks helped confirm the accuracy of the data. There were two types of inspections:
  • Type One Inspections focused on sites with deployed (ready-to-use) weapons.
  • Type Two Inspections looked at sites with non-deployed weapons.
• Meeting Limits: Both countries had seven years to reach the agreed-upon limits for warheads and delivery vehicles. By February 2018, both the United States and Russia had successfully met these reduction goals.

Monitoring and Verification of New START

Monitoring and verification were very important parts of the New START treaty. Both the United States and Russia could inspect each other's military bases. These inspections helped ensure that each country was following the rules.

Since 2011, both countries made steady progress in reducing their nuclear weapons. By February 2018, they had both reached their reduction targets. The treaty also made public information about the total numbers and locations of nuclear weapons. This transparency helped build trust between the two nations.

Efforts to Extend the Treaty

Over the years, there were discussions about extending the New START treaty.

• 2017: U.S. President Donald Trump initially expressed doubts about extending the treaty.
• 2019-2020: Discussions continued, with some talks about including China in a future agreement. Russia offered to extend the treaty without changes.
• 2021: On January 26, U.S. President Joe Biden and Russian President Vladimir Putin agreed to extend the treaty for five more years. This meant the treaty would remain active until February 5, 2026. Both countries quickly approved this extension.
• 2022: In November, Russia postponed a meeting with the U.S. to discuss resuming inspections. This happened as relations between the two countries became difficult after the conflict in Ukraine.

Suspension and Aftermath

On February 21, 2023, President Vladimir Putin announced that Russia was suspending its participation in New START. He stated that Russia would not allow the U.S. and NATO to inspect its nuclear facilities. Putin claimed the United States was developing new nuclear weapons. He also warned that Russia would develop and test its own if the U.S. conducted any nuclear weapons tests.

U.S. Secretary of State Antony Blinken called Russia's decision "unfortunate and very irresponsible." Jens Stoltenberg, the head of NATO, urged Russia to reconsider. Despite the suspension, Russia stated it would continue to follow the numerical limits of the treaty. However, on March 29, 2023, Russia announced it would stop sharing notifications about its missile deployments.

Expiration of the Treaty

The New START treaty officially expired on February 5, 2026. This meant that the legally binding limits on strategic nuclear weapons between the United States and Russia were no longer in effect.

In September 2025, President Vladimir Putin had suggested that Russia would continue to observe the treaty's limits for one year after its expiration. This was conditional on the United States making a similar commitment. However, the United States did not formally accept or reject this proposal. President Donald Trump, in late 2025, commented positively on the idea of nuclear restraint but did not commit to continued compliance. In January 2026, he indicated that the treaty's expiration was not a top priority.

Russian officials had warned that without a replacement, the expiration of New START would increase strategic risks. On February 4, 2026, Russia's Ministry of Foreign Affairs stated that, without a formal U.S. response, Russia considered the treaty's obligations no longer binding. Russia indicated it would decide its future actions based on the global situation.

International Reactions to Expiration

• Russia: The Russian Ministry of Foreign Affairs stated that Russia intended to act responsibly. However, it warned of "decisive countermeasures" if its national security was threatened.
• United States: U.S. Secretary of State Marco Rubio called for a new treaty. He suggested that China should also be part of this new agreement.
• United Nations: UN Secretary-General António Guterres urged the United States and Russia to quickly create a new nuclear arms control treaty.
• Vatican: Pope Leo XIV asked both countries to do everything possible to prevent a new arms race.

Images for kids

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  Obama administration officials discussing the New START Treaty at a meeting

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  Vladimir Putin announcing the plans to suspend Russia's participation in the New START treaty during his February 2023 speech

See also

In Spanish: START III para niños

• 2010 NPT Review Conference
• Strategic Arms Limitation Talks (SALT I and II)
• Treaty of Moscow (2002)