Illustration: Aïda Amer/Axios

The mushroom clouds over Hiroshima and Nagasaki have remained unreplicated for 75 years in part because the U.S. and Soviet Union — after peering over the ledge into nuclear armageddon — began to negotiate.

Why it matters: The arms control era that began after the Cuban Missile Crisis may now be coming to a close. The next phase could be a nuclear free-for-all.

Driving the news: New START, the last major pact constraining the U.S. and Russia — which together hold 91% of the world's nuclear warheads — is due to expire two weeks into the next presidential term, on Feb. 5.

  • President Trump has insisted on a new, larger deal that also constrains China — which has a far smaller program, but one that U.S. intelligence expects to grow quickly.
  • Beijing balked at American pressure to join recent U.S.-Russia nuclear talks in Vienna.
  • Trump has recently held a flurry of phone calls with Vladimir Putin, and he suggested last week that he might support a deal involving only the U.S. and Russia.
  • His top aides continue to insist on Chinese participation and to resist Putin's proposal for an unconditional extension.

Where things stand: Joe Biden on Thursday reiterated his commitment to extending New START if elected (he'd have 15 days to exchange diplomatic notes with Russia). Its fate would be far more uncertain in a second Trump term.

What they're saying: Rose Gottemoeller, the chief U.S. negotiator for New START under Barack Obama, says China won't rush to the negotiating table before February.

  • "It’s not rational, it’s not logical and they have absolutely no incentive to do so," she told Axios.
  • Meanwhile, "the Russians have just finished the modernization of their nuclear arsenal," and have "hot production lines."
  • “We could soon be facing a Russia who is far superior to us in nuclear numbers," she says, if the deal lapses.

Tim Morrison, who held both the arms control and Russia portfolios on Trump’s National Security Council, says those demanding a clean extension of New START might as well enter a car dealership and declare: "I am not leaving here until you sell me a car, no matter the price."

  • China and Russia fear Washington's deep pockets and the prospect of an unconstrained American arsenal, he says. That offers leverage.
  • America, meanwhile, has reason to fear Russia's fast-advancing capabilities (not covered by New START) and China's burgeoning nuclear buildup.
  • That explains the administration's emphasis on a new deal and its willingness to take the old one to the brink. “I am simply not in the panic that some people are to extend the treaty now," Morrison says.

The big picture: The expiration of New START — paired with Trump's withdrawal from the Open Skies and Intermediate-Range Nuclear Forces treaties (the latter due to Russian violations) — would signal the end of arms control as we know it.

  • If the arms control infrastructure built up during the Cold War collapses, it may be impossible to reassemble.
  • Morrison, now a senior fellow at the Hudson Institute, acknowledges that. But he points the finger at Moscow: “If arms control is dying, it’s because Russia killed it."

Even if New START survives, we are heading into a new, more uncertain era.

  • As communications channels break down and new technologies are built up, "the possibilities of a miscalculation are unfortunately higher than they have been in a long, long time," Ernest Moniz, the nuclear physicist and former energy secretary, tells Axios.

What to watch: Emerging technologies like cyber warfare and AI portend an uncertain future.

  • Meanwhile, arsenals of smaller-yield nukes are growing, including among newer nuclear powers like India and Pakistan. "They were built for battlefield use and so seem to lower the threshold for nuclear use," Gottemoeller says.
  • North Korea has entered the nuclear club, and others could follow. Those include Iran and Saudi Arabia, which is working with China to increase its capacity to generate nuclear fuel, the NYT reports.
  • With Russia boasting of "unstoppable" weapons and China working to narrow the nuclear gap, America is undertaking a modernization process which could cost $1.7 trillion over 25 years, Jessica Mathews writes in the New York Review of Books.

The bottom line: "Yet the public isn't scared," Mathews notes. "Decades of fearing a nuclear war that didn’t happen may have induced an unwarranted complacency that this threat belongs to the past."

Go deeper: How new tech raises the risk of nuclear war

Go deeper

Oct 26, 2020 - World

China to sanction Boeing, Lockheed Martin, Raytheon over Taiwan arms sales

Taiwan's President Tsai Ing-wen during a visit to Penghu Air Force Base. Photo: Sam Yeh/AFP via Getty Images

China plans to impose unspecified sanctions on Boeing, Lockheed Martin, Raytheon and other U.S. companies involved in weapons sales to Taiwan, Reuters reports, citing a Chinese Foreign Ministry spokesperson.

Why it matters: The Trump administration last week notified Congress of an additional $1.8 billion in proposed arms sales to Taiwan. China's recent military exercises and the buildup of forces along its southeastern coast have renewed fears of an invasion of Taiwan, which Beijing views as a breakaway province that must be brought under its control.

Zeta, now a Category 2 Hurricane, makes landfall on Louisiana coast

The probable path of Zeta, per the National Hurricane Center. Photo: NHC/NOAA

Zeta, classified as a "significant" Category 2 hurricane, made landfall along the southeastern coast of Louisiana on Wednesday evening, according to the National Hurricane Center.

The state of play: Louisiana Gov. John Bel Edwards (D) requested a pre-landfall Emergency Declaration in a letter to President Trump on Tuesday. The hurricane is producing 110-mph maximum sustained winds and stronger gusts. The core of Zeta — including its destructive eyewall — moved ashore near Cocodrie.

Supreme Court won't expedite Pennsylvania GOP's request to block mail-in ballot extension

Amy Coney Barrett being sworn in by Chief Justice John Roberts. Photo: Fred Schilling/Collection of the Supreme Court of the United States via Getty Images

The Supreme Court voted 5-3 on Wednesday to deny a bid from Pennsylvania Republicans to expedite their request to shorten the deadline for receiving mail-in ballots. Newly-confirmed Justice Amy Coney Barrett did not participate in the decision.

Why it matters: A lower court ruling allowing ballots to be counted until 5 p.m. on Nov. 6, as long as they are postmarked by Election Day, will remain in place for now. Conservative Justices Alito, Thomas and Gorsuch wrote in a separate opinion that it's too close to the election to take up the case, but it could still be reviewed after the election if late-arriving ballots make a difference.