PARIS (AP) — The head of Britain’s foreign intelligence service said Friday that Russia is conducting a “staggeringly reckless” sabotage campaign against Ukraine's Western allies, and that his spies are working to stop the consequences from spiraling out of control.

MI6 chief Richard Moore said his agency and its French counterpart were working together to prevent a dangerous escalation by “calibrating the risk and informing the decisions of our respective governments” in response to President Vladimir Putin’s “mix of bluster and aggression.”

“We have recently uncovered a staggeringly reckless campaign of Russian sabotage in Europe, even as Putin and his acolytes resort to nuclear saber-rattling, to sow fear about the consequences of aiding Ukraine,” Moore said during a speech to diplomats and intelligence officials in France.

“Such activity and rhetoric is dangerous and beyond irresponsible,” he said.

Moore spoke alongside Nicolas Lerner, head of France’s external intelligence agency, the DGSE at an event marking 120 years of the Entente Cordiale, a pact between Britain and France that bound the age-old rivals together as military and diplomatic allies.

Western security officials suspect that Russian intelligence is trying to destabilize Ukraine’s allies through disinformation, sabotage and arson.

Moscow has been linked by Western officials to several planned attacks in Europe, including an alleged plot to burn down Ukrainian-owned businesses in London, and to incendiary devices in packages on cargo planes. In July one caught fire at a courier hub in Germany and another ignited in a warehouse in England.

Lerner agreed that “the collective security of the whole of Europe is at stake” in Ukraine. He said Britain’s experience tackling Russia in the wake of recent attacks like the 2018 Salisbury Novichok poisoning, was invaluable to French intelligence seeking to defuse Russian actions.

Britain and France have been among Ukrainian allies most willing to allow Kyiv to use weapons they supply – especially missiles known as Scalp in France and Storm Shadow in Britain – to hit targets inside Russia. The Biden administration recently eased its long-held opposition to U.S.-made missiles being used to strike Russia. Ukraine said last week it had used the American ATACM missiles to target Russia for the first time in the war.

Since then, Russia has pounded Ukraine’s energy infrastructure with hundreds of missiles and drones, in what Putin said was a response to the firing of the American missiles against Russian soil. Russia also fired a new intermediate-range ballistic missile, called Oreshnik, and Putin threatened to use it against “decision-making centers” in Kyiv, the Ukrainian capital.

In a warning to allies wavering in support for Ukraine, Moore said that “the cost of supporting Ukraine is well-known, but the cost of not doing so would be infinitely higher.”

He said that if Russia wins, Iran and China — which so far support Moscow as “a transaction" — would draw closer to Russia.

“If Putin succeeds, China would weigh the implications, North Korea would be emboldened and Iran would become yet more dangerous,” Moore said.