The message to NATO from President Vladimir Putin was simple and stark: Don’t go too far in providing military support for Ukraine, or you’ll risk a conflict with Russia that could quickly turn nuclear. As the war in Ukraine turns slowly in Moscow’s favor, Putin declared he doesn´t need nuclear weapons to achieve his goals. But he also says it’s wrong for the West to assume that Russia will never use them. “It mustn´t be treated in a light, superficial way,” Putin said in June, reaffirming that Russia’s nuclear doctrine calls for using atomic weapons if it perceives a threat to its sovereignty and territorial integrity. Moscow´s nuclear messaging – coming as NATO allies move to shore up exhausted and outgunned Ukrainian forces – heralds what could become the most dangerous phase in the war. Moscow has carried out drills with its tactical – or battlefield – nuclear weapons in southern Russia and with ally Belarus, where some were deployed in 2023. Russian Defense Ministry videos showed Iskander missile launchers, nuclear-capable warplanes and sea-launched missiles. The Kremlin described the exercises as a response to the West pondering the deployment of NATO troops to Ukraine and allowing Kyiv to use longer-range weapons for limited strikes on Russian territory. “Reliance on nuclear threats and signals is an enduring trend in Russia´s activities amid the war in Ukraine,” said Heather Williams, senior fellow at the Washington-based Center for Strategic and International Studies. “Russian leadership may be assuming it has more at stake in Ukraine than NATO, and nuclear threats are one means of signaling its commitment to winning the war in the hopes of scaring off Western intervention.” Ever since launching the Feb. 24, 2022, invasion, Putin has repeatedly referred to Russia´s nuclear might to discourage Western intervention. The United States and NATO criticized the nuclear saber-rattling but said they haven’t seen any changes in Russia’s nuclear posture warranting a response. After early setbacks in Ukraine, Putin said Moscow was prepared to use “all means” to protect Russian territory, fueling fears he could turn to tactical nuclear weapons to halt Kyiv’s advances. Putin later toned down his rhetoric after Ukraine’s 2023 counteroffensive didn’t achieve its goals. Amid Russia’s recent military successes, Putin said Moscow doesn´t need nuclear weapons to win in Ukraine. Simultaneously, however, he warned that Kyiv’s strikes on Russian soil with Western-supplied longer-range weapons would mark a major escalation because they would involve Western intelligence and military personnel – something the West denies. “Representatives of NATO members, particularly in small countries of Europe, should be aware of what they are playing with,” he said, adding they could be mistaken to rely on U.S. protection if Russia strikes them. “The constant escalation could lead to grave consequences,” he said. “If those grave consequences come to Europe, how will the U.S. act in view of our parity in strategic weapons? Hard to say. Do they want a global conflict?” In May, Russian radar facilities were attacked by Ukrainian drones. One damaged a radar in the southern Krasnodar region, according to satellite images. Another targeted a similar facility in the southern Urals, about 1,500 kilometers (930 miles) east of the border. Both are part of Russia´s early warning system to spot intercontinental ballistic missile launches thousands of kilometers (miles) away. Moscow and Washington rely on such systems to track each other´s launches. Along with earlier Ukrainian raids on Russian nuclear-capable bomber bases, the radar strikes could qualify as triggers for atomic-weapons use under Moscow’s nuclear doctrine. Russian hawks urged the Kremlin to respond forcefully. At a June forum in St. Petersburg, Kremlin-connected foreign policy expert Sergei Karaganov urged Putin to “aim a nuclear pistol at our Western adversaries” to achieve victory in Ukraine.