Moscow has threatened to retaliate against the US and UK’s decision to allow their long-range missiles to be used in strikes inside Russian territory and warned that nothing is off the table, according to a Guardian analysis. Earlier this week, the Kremlin announced a formal change to its nuclear doctrine, which specifically provides for a possible nuclear response to NATO-assisted attacks on Russian soil. So how far is Russian President Vladimir Putin willing to go?

How likely is Russia to use nuclear weapons in Ukraine?

The Kremlin has touted its strategic arsenal during the Ukrainian conflict in an effort to prevent Western involvement. But despite all the threats, the US has reported seeing no signs of unusual movement at Russian nuclear weapons storage facilities, suggesting there has been no change in the physical placement of nuclear warheads.

Most analysts see Russia’s use of nuclear weapons as unlikely for now, but caution against complacency. Pavel Podvig, a senior researcher at the UN’s Institute for Disarmament Research, said he did not believe dropping a bomb on Ukraine included in the Moscow options “mainly because it would not help achieve military objectives, and the Russia making progress on the front for now.”

Additional, using a nuclear weapon in a conflict for the first time since 1945 would unite much of the world against Russia in ways Moscow could not easily foreseePodvig argued. “Therefore, such a decision would be a big gamble. However, I cannot rule out that the Kremlin is willing to risk it. Especially if Moscow feels it can count on a weak response. We don’t know if that’s the case.”he said via the social networking platform Bluesky.

In what other ways can Russia respond to the West?

Moscow has shown great imagination in using hybrid tactics against its enemies.

He has used the flow of refugees as a weapon, directing them to the borders of Poland, Lithuania and Finland with the aim of causing political unrest in those countries.

Russian military intelligence has also carried out assassinations in the UK, Germany, Spain, Austria, Turkey and elsewhere. He has planned sabotage attacks, which reportedly included the use of incendiary devices found in Germany and the UK in July. Western intelligence agencies believe the attempted bombings were a test for similar potential attacks on flights to North America.

In the US and Europe, Russian online bots have intensified polarization on various issues, aiming to loosen social cohesion and strengthen the far right. Russia has also been accused of jamming GPS signals, especially over the Baltic, disrupting the navigation of thousands of passenger aircraft.

On Wednesday, Danish authorities named a Chinese cargo ship as the closest to the Baltic Sea area where two undersea fiber optic cables were cut earlier this week. However, Elisabeth Braw, an expert at the Atlantic Council, said this does not rule out Russian involvement. “Commercial ships don’t usually go and cut submarine cables for fun,” Braw said. “What we’ve seen is that Russia is very good at using proxies.”

What allies and proxies can Russia use?

Moscow has a history of working ad hoc with allies and proxies to conduct business in the West. According to a Wall Street Journal report last month, Russia provided targeting data to Yemen’s Houthi rebels for attacks on Western ships in the Red Sea.

In the UK, the head of MI5, the domestic security agency, said in October that Russian intelligence services had significantly stepped up their cooperation with criminal gangs as part of “an ongoing mission to create chaos on British and European streets: we’ve seen arson, sabotage and more.”

How can Western countries respond to Russian hybrid warfare?

The fact that these hybrid warfare operations are conducted through the use of proxies and denial of responsibility makes them particularly difficult to counter. A criminal investigation does little to hold Moscow accountable, and the intelligence services of Western democracies are largely constrained from reacting in kind.

“We’re just not going to jam Russian navigation signals at sea or in the air, because that could cause accidents”Braw said. “The Russians are very good at this. They continue to innovate. It is very difficult to find ways on how to punish them.”