The U.S. and other world leaders issued a joint declaration Wednesday condemning Russia’s war in Ukraine and denouncing threats of using nuclear weapons, an intimidation tactic that’s become commonplace for Russian President Vladimir Putin since launching his invasion nine months ago.
“The use or threat of use of nuclear weapons is inadmissible,” read the statement, composed by the world’s 20 largest economies. “The peaceful resolution of conflicts, efforts to address crises, as well as diplomacy and dialogue, are vital. Today’s era must not be of war.”
The 17-page document marks a victory for the Biden Administration and global allies, which sought to end this year’s summit in Bali, Indonesia with a statement censuring Russia for its unprovoked military campaign in Ukraine. In recent weeks, the Biden team has launched a discreet, multi-pronged effort to pressure Moscow to dial back the increasingly reckless bluster that has sparked fears the world was nearing the brink of nuclear war. Through a series of one-on-one discussions and back channels between top U.S. and Russian officials, combined with diplomatic maneuvering with other nations’ leaders, the Administration has worked to get Putin and his government to stop threatening the use of nuclear weapons on the battlefield in Ukraine, where Moscow has faced mounting losses this fall.
In a rare disclosure on Monday, the White House revealed CIA Director William Burns met with his Russian counterpart Sergey Naryshkin in Ankara, Turkey’s capital, to discuss potential costs to the Kremlin if it decides to use a nuclear weapon in the Ukraine conflict. “He is not conducting negotiations of any kind,” a White House spokeswoman said. “He is conveying a message on the consequences of the use of nuclear weapons by Russia, and the risks of escalation to strategic stability.”
The same day, President Joe Biden and Chinese President Xi Jinping issued a joint-statement that said nuclear weapons should never be used, particularly in Ukraine. The rebuke was noteworthy considering Beijing has tacitly approved of Putin’s actions and shown reticence to join the international community’s widespread condemnation of invasion.
Read more: U.S. Unveils Strategy for Nuclear Threats from China and Russia
The message the U.S. seeks to send is clear: if Moscow goes nuclear in Ukraine, it will only experience further economic and diplomatic isolation on the world stage. There are indications that the strategy, which has gathered momentum behind the scenes since late September after Putin illegally annexed four occupied regions of Ukraine then suggested he’d defend the territory with nuclear arms, may be working. Putin backtracked late last month by stating Russia would gain nothing through launching a nuclear strike. “We see no need for that,” he said Oct. 27 at a conference of international foreign policy experts. “There is no point in that, neither political nor military.”
Concerned observers are cautiously optimistic that the U.S. approach will continue to draw Putin away from the nuclear threshold, but they worry about the ongoing instability of relations between the world’s foremost nuclear powers. “The Biden team has been effective in cautioning Putin not to cross the nuclear line, warning of the consequences, and quietly encouraging others with influence like China to provide similar messages to Putin. They’ve done this very adeptly while avoiding provocations,” says Lynn Rusten, vice president at the Nuclear Threat Initiative and former senior official on arms control and nonproliferation issues at the White House and State Department. “But they must stay vigilant. The crisis may have passed, but the risk of nuclear use will remain as the war grinds on.”
All of Putin’s threats have thus far appeared to be primarily for show—U.S. intelligence has yet to observe changes in the posture of Russia’s strategic arsenal—but the prospect of the world’s most powerful weapon being detonated cannot be disregarded. Biden has sought to avoid nuclear escalation with Russia ever since the first chaotic days of the war. Around 90% of the world’s nuclear warheads belong to Russia and the United States, and these arsenals loom large over U.S. strategy posture as the Biden seeks to keep pressure on Putin to stop his blood-soaked military campaign.
The Administration has sought to strike a balance between supporting Ukraine with weapons and intelligence information without sparking nuclear escalation or an open war with Russia. The Biden team has been forced to adapt the strategy at nearly every turn in the conflict and determine how far the U.S. can go without crossing Putin’s red lines.
In March, the Biden Administration postponed a long-planned military test launch of an intercontinental ballistic missile out of fears that Russia would see it as threatening. A week later, the U.S. rejected a proposal to provide the Ukrainian Air Force with 28 MiG-29 fighter jets for similar reasons. The President dismissed calls to establish a no-fly zone in the skies above Ukraine because it would bring American pilots in direct combat with Russian pilots. And throughout the war, Biden has restrained from engaging in tit-for-tat nuclear threats in response to Putin’s rhetoric.
Read More: Inside the $100 Billion Mission to Modernize America’s Aging Nuclear Missiles
Instead, Biden’s National Security Adviser Jake Sullivan has privately relayed to Russian officials the potential consequences for launching a nuclear strike in Ukraine. In public, the Administration has refused to detail what penalties Russia would face for using a nuclear weapon—a catastrophe that hasn’t occurred since the U.S. dropped two atomic bombs on Japan in 1945.
Expressing these messages in private while outwardly harnessing a coalition of nations to denounce Russia’s potential nuclear use is proving to be an effective strategy thus far, says George Perkovich, vice president for studies at the Carnegie Endowment for International Peace, a Washington non-profit. “But it’s still early,” he says. “Unfortunately, we’re not at a point where the risk of Russia using nuclear weapons is zero.”
Over the last several months, the Russian military has suffered a series of embarrassing defeats in Ukraine and late last week withdrew from the region west of the Dnipro River. If Putin’s forces continue to be bogged down fighting a smaller, less capable Ukrainian army, many experts fear the danger of a wider, more calamitous confrontation with the West will rise. But the winter weather is expected to pause fighting, which may provide an opening for peace talks between Ukraine and Russia.
The return of nuclear brinkmanship on the global stage has reminded the world of the Cuban missile crisis, which is the last time the superpowers neared nuclear war. The showdown, now 60 years ago, did not develop into a shooting war or a nuclear exchange. Can we once again avert such a disaster and come upon a diplomatic resolution? Such an ending seems remote amid Russia’s daily bombardment of Ukrainian cities and the mass violence there. But to survive the current conflict, the lessons of the past must be reexamined.
At the end of the Cuban missile crisis, the U.S. and Soviet Union opened numerous communication channels, and established several treaties around nuclear weapons and other issues of mutual concern through prolonged diplomacy—despite being sworn adversaries. “The road we’re on now is long and has a lot of curves ahead,” Perkovich says. “So I don’t know if we’ll get there, but we should at least try.”
More Must-Reads from TIME
- How Donald Trump Won
- The Best Inventions of 2024
- Why Sleep Is the Key to Living Longer
- Robert Zemeckis Just Wants to Move You
- How to Break 8 Toxic Communication Habits
- Nicola Coughlan Bet on Herself—And Won
- Why Vinegar Is So Good for You
- Meet TIME's Newest Class of Next Generation Leaders
Write to W.J. Hennigan at william.hennigan@time.com