Putin has previously threatened to resort to nuclear weapons if Russia’s goals in Ukraine continue to be thwarted. The annexation brings the use of a nuclear weapon one step closer by giving Putin a possible justification on the grounds that “the territorial integrity of our country is threatened,” as he put it in a speech last week. He renewed the threat on Friday with an ominous comment that the US atomic bombing of Hiroshima and Nagasaki set a “precedent” for the use of nuclear weapons, echoing his past references to the US invasion of Iraq as a precedent for Russia’s invasion of Ukraine. American and Western officials say they still think it unlikely that Putin will carry out his threats. More likely, they say, he hopes to deter the West from providing increasingly sophisticated military aid to Ukraine, while mobilizing an additional 300,000 troops allows Russia to reverse or at least halt its military failures on the battlefield. Three maps explaining Russia’s annexations and losses in Ukraine However, the threats appear to have strengthened Western resolve to continue sending arms to Ukraine, and the Ukrainian military continues to advance into Russian-held territory. On Saturday, the Ukrainian army seized control of the eastern city of Liman in an area apparently annexed by Russia on Saturday. The collapse of another Russian front line was greeted by calls for nuclear strikes from some military bloggers and political figures in Russia, including Chechen leader Ramzan Kadyrov, a close ally of Putin. “More drastic measures should be taken, up to the declaration of martial law in the border areas and the use of low-yield nuclear weapons,” Kadyrov wrote in a comment on his Telegram channel. Russian troops withdraw from Liman, a day after claims of annexation In all four regions Putin said he was annexing — Donetsk, Luhansk, Kherson and Zaporizhia — Russia controls only part of the territory. Now that the territories being fought over are seen by Moscow as Russian, it is possible to chart the course of events towards the first use of a nuclear weapon since the atomic bombing of Japan in 1945. “It’s a low-probability event, but it’s the most serious case of a nuclear brinkmanship since the 1980s,” when the Cold War ended, said Franz-Stefan Gady, a senior fellow at the International Institute for Strategic Studies in London. “It is a very dangerous situation and should be taken seriously by Western policy makers.” US and European officials say they are taking the threats seriously. White House national security adviser Jake Sullivan said Sunday that there would be “catastrophic consequences” if Russia resorted to using nuclear weapons. He declined to specify what those would be, but said the exact consequences had been spelled out privately to Russian officials “at very high levels.” “They understand well what they would face if they went down that dark path,” he said. The US has sent private warnings to Russia against using a nuclear weapon European officials say the threats have strengthened their resolve to support Ukraine. “No one knows what Putin will decide to do, no one,” said a European Union official who spoke on condition of anonymity to discuss a sensitive issue. “But he’s completely cornered, he’s mad… and for him there’s no way out. The only way out for him is total victory or total defeat and we are working towards the latter. We need Ukraine to win, so we are working to prevent worst-case scenarios by helping Ukraine win.” The goal, the official said, is to give Ukraine the military support it needs to continue pushing Russia out of Ukrainian territory while politically pressuring Russia to agree to a cease-fire and withdrawal, the official said. And the pressure is working, “slowly,” the official said, to spread awareness in Russia and internationally that the invasion was a mistake. India, which appeared to be on Russia’s side in the early days of the war, has expressed concern over Putin’s talk of nuclear war, and China, ostensibly Russia’s most important ally, has signaled it is uneasy with continued escalations of Putin. But the attachment and mobilization of hundreds of thousands of additional troops also served as a reminder that Western strategy has not yet worked enough to convince Putin that he cannot win, said Alexander Gabuev, a senior fellow at the Carnegie Endowment. for International Peace which was based in Moscow until the beginning of the year. The West had hoped that the Ukrainian successes would force Putin to back down, but instead he is doubling down. “We find time and time again that Vladimir Putin sees this as a big existential war and is ready to raise the stakes if he loses on the battlefield,” Gabuev said. “At the same time I don’t think the West will back down, so it’s a very difficult challenge now. We are two or three steps away’ from Russia failing to achieve its goals and resorting to what was once unthinkable. These steps to secure its positions include Russia pushing hundreds of thousands more men into the battlefield. escalating attacks on civilian targets and infrastructure in Ukraine; and perhaps also launching covert attacks on Western infrastructure. Although the United States and its European allies have refrained from making direct accusations, few doubt that Russia was behind the sabotage of the Nord Stream pipelines in the Baltic Sea, the EU official said. “I don’t think anyone has doubts. It is the Kremlin’s handwriting,” he said. “It’s a sign of ‘look what’s coming, look what we can do.’ “ Nuclear weapons will likely be used only after mobilization, sabotage and other measures have not turned the tide, and it is unclear what Putin would achieve by using them, Gandhi said. Despite some wild predictions in the Russian news that the Kremlin would attack a Western capital, with London appearing to be a favored target, it is more likely that Moscow will seek to use one of its smaller, tactical nuclear weapons on its range battle. try to gain an advantage over the Ukrainian forces, Gandhi said. The smallest nuclear weapon in Russia’s arsenal emits a blast of about 1 kiloton, one-fifteenth the size of the bomb dropped on Hiroshima, which would cause mass destruction but in a more limited area. Because the war is being fought along a vast 1,500-mile front line, troops are too thinly spread for there to be an obvious target whose elimination would change the course of the war. To make a difference, Russia would have to use multiple nukes, or alternatively hit a major population center like Kyiv, of which it would represent a massive escalation, almost certainly trigger Western retaliation, and turn Russia into a pariah state even with her allies. Gandhi said. “From a purely military perspective, nuclear weapons would not solve any of Vladimir Putin’s military problems,” he said. “To change the operational picture a single attack would not be enough and also would not intimidate Ukraine into handing over territory. It would cause the opposite, it would double the support of the West and I think there would be a US response.” That is why many believe that Putin will not carry out his threats. “Although Putin is dangerous, he is not suicidal and those around him are not suicidal,” said Ben Hodges, former commander of US forces in Europe. Pentagon officials said they have seen no actions by Russia that would lead the United States to adjust its nuclear posture. Robyn Dixon contributed to this report from Riga, Latvia

War in Ukraine: What you need to know

The last: Russian President Vladimir Putin signed decrees on Friday to annex four occupied regions of Ukraine, following organized referendums widely denounced as illegal. Follow our live updates here. The answer: The Biden administration on Friday announced a new round of sanctions on Russia in response to the annexations, targeting government officials and family members, Russian and Belarusian military officials and defense procurement networks. President Volodymyr Zelensky also said on Friday that Ukraine is applying for “fast-track accession” to NATO, in an apparent response to the annexations. In Russia: Putin declared a military mobilization on September 21 to call up up to 300,000 reservists in a dramatic bid to reverse setbacks in his war against Ukraine. The announcement led to an exodus of more than 180,000 people, mostly servicemen, and renewed protests and other acts of defiance against the war. The battle: Ukraine mounted a successful counteroffensive that forced a large Russian retreat in the northeastern Kharkiv region in early September, as troops abandoned towns and villages they had seized since the early days of the war and abandoned large quantities of military equipment. Photos: Washington Post photographers have been on the ground since the start of the war — here are some of their strongest works. How you can help: Here are ways those in the US can support the Ukrainian people, as well as what people around the world are donating. Read his full coverage Russia-Ukraine war. Are you on Telegram? Subscribe to our channel for updates and exclusive video.