The last remaining nuclear-arms treaty between the U.S. and Russia is on track for a five-year extension. President Joe Biden and Russian President Vladimir Putin agreed to extend so-called New START in their first exchange since Biden took office on Jan. 20. Biden’s predecessor, Donald Trump, had sought to renegotiate the deal, which is due to expire on Feb. 5. He wasn’t alone, as policy makers across the political spectrum have called for improvements.

1. What is New START?

The U.S. and Russia signed New START -- also called the New Strategic Arms Reduction Treaty -- in 2010, to replace the 1991 START treaty. New START took effect on Feb. 5, 2011, and included wording allowing the two parties to extend it for five more years. Under the accord, the U.S. and Russia both committed to reducing deployed nuclear warheads (which are capped at 1,550 each) and limiting the number of delivery platforms such as submarine launchers, intercontinental ballistic missiles and bombers. The agreement also allows each country to conduct on-site inspections of each other’s weaponry and requires the exchange of data and notification concerning covered arms and facilities.

2. Has it worked?

Yes. The U.S. and Russia reduced their nuclear arsenals to the agreed-upon limits by the 2018 deadline set forth in the treaty. The U.S. had 1,457 deployed warheads and 675 deployed strategic delivery systems as of Dec. 1, 2020, according to the U.S. State Department. Russia had 1,447 deployed warheads attributed to 510 deployed strategic launchers. Combined, the two countries account for about 90% of the world’s nuclear weapons.

3. What happens if New START isn’t extended?

The two nations would lose up-to-date information about each other’s arsenals, which potentially could trigger a new arms race.

4. What has to happen?

The text of the treaty gives Biden, as president, the authority to extend the treaty without seeking approval from Congress. Putin needed approval from Russia’s parliament, which he received on Jan. 27.

5. What did the Trump administration want?

It called the treaty “deeply flawed” in part because it addresses only strategic nuclear weapons -- long-range ones that can be used to threaten each other’s territory -- and not shorter-range, so-called tactical weapons. Russia’s tactical arsenal is much greater than that of the U.S. The Trump administration had hoped, as part of negotiations over extending New START, to force Russia to agree to a freeze in its overall number of nuclear warheads. Another hope of the Trump team was to expand the agreement to include China, but leaders in Beijing declined to engage in talks.

6. Does Biden not share those concerns?

Biden administration officials say extending New START shouldn’t hinge on China joining the pact, though they acknowledge it’s important to address the expansion and modernization of China’s nuclear forces. Estimates of China’s nuclear warheads range from around 200 to as many as 350, and the U.S. sees China doubling that stockpile in the next decade. As for the question of trying to limit Russia’s tactical nuclear weapons, even some Biden aides are on record sharing that concern. Victoria Nuland, Biden’s nominee to serve as under secretary for political affairs at the State Department, wrote in Foreign Affairs last year that the U.S. “should not grant Moscow what it wants most: a free rollover of New START without any negotiations to address Russia’s recent investments in short- and medium-range nuclear weapons systems and new conventional weapons.”

7. What does this mean for other arms control agreements?

New START is the last standing arms control agreement between Russia and the U.S. The Trump administration withdrew the U.S. from two others -- the Intermediate-Range Nuclear Forces (INF) Treaty, signed in 1987 by U.S. President Ronald Reagan and Soviet leader Mikhail Gorbachev, and the Open Skies Treaty, under which more than 30 nations grant each other access to airspace for the purpose of collecting information on military activities. Biden said he plans to use New START as a framework for future agreements. His secretary of state, Antony Blinken, supports “staying engaged” in the Open Skies treaty and criticized Trump’s decision to withdraw from the INF Treaty.

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