The heads of the British and American foreign intelligence agencies said Saturday that Ukraine’s surprise incursion into Russia is a significant achievement that could change the narrative of the grinding 2 1/2-year war, as they urged Kyiv’s allies not to be held back by Russian threats of escalation.

Richard Moore, the head of MI6, said Kyiv’s surprise August offensive to seize territory in Russia’s Kursk region was “typically audacious and bold on the part of the Ukrainians, to try and change the game.” He said the offensive — which Ukraine said has captured about 1,300 square kilometers (500 square miles) of Russian territory — had “brought the war home to ordinary Russians.”

Speaking alongside Moore at an unprecedented joint public event in London, CIA Director William Burns said the offensive was a “significant tactical achievement” that had exposed vulnerabilities in the Russian military.

It has yet to be seen whether Ukraine can turn the gains into a long-term advantage. So far the offensive has not drawn Russian President Vladimir Putin’s focus away from eastern Ukraine, where his forces are closing in on the strategically situated city of Pokrovsk.

Ukrainian President Volodymyr Zelenskyy has repeatedly pressed allies to let Kyiv use Western-supplied missiles to strike deep inside Russia and hit sites from which Moscow launches aerial attacks. While some countries, including Britain, are thought to tacitly support the idea, others including Germany and the U.S. are reluctant.

U.S. President Joe Biden has allowed Ukraine to fire U.S.-provided missiles into Russia in self-defense, but the distance has been largely limited to cross-border targets deemed a direct threat, out of concerns about further escalating the conflict.

Burns said the West should be “mindful” of the escalation risk but not be “unnecessarily intimidated” by Russian saber-rattling, revealing that there was a moment in late 2022 when there was a “genuine risk of the use of tactical nuclear weapons” by Moscow.

He also warned of the growing and “troubling” defense relationship between Russia, China, Iran and North Korea that he said threatens both Ukraine and Western allies in the Middle East. North Korea has sent ammunition and missiles to Russia to use against Ukraine, while Iran supplies Moscow with attack drones.

Burns said the CIA had yet to see evidence of China sending weapons to Russia, “but we see lot of things short of that.” And he warned Iran against supplying ballistic missiles to Moscow, saying “it would be a dramatic escalation” of the relationship.

He did not say whether such missiles had already been sent. But two people familiar with the matter said the United States has told allies that it believes Tehran has transferred short-range ballistic missiles to Russia. They spoke on condition of anonymity to discuss a matter that has not been publicly disclosed.

Ahead of their joint appearance at the FT Weekend Festival at London’s Kenwood House, the two spymasters wrote an opinion piece for the Financial Times, calling for a cease-fire in Israel’s war against Hamas and saying their agencies had “exploited our intelligence channels to push hard for restraint and de-escalation.”

Burns has been heavily involved in efforts to broker an end to the fighting, traveling to Egypt in August for high-level talks aimed at bringing about a hostage deal and at least a temporary halt to the conflict.

So far there has been no agreement, though United States officials insist a deal is close. Biden said recently that “just a couple more issues” remain unresolved. Israeli Prime Minister Benjamin Netanyahu, however, has said reports of a breakthrough are “exactly inaccurate.”

“I cannot tell you how close we are right now,” Burns told the London audience. He said negotiators are working on new, detailed proposals that would be presented within several days.

Burns said that while 90% of the text has been agreed between the warring sides, “the last 10% is the last 10% for a reason, because it’s the hardest part to do.”

Burns said ending the conflict would require “some hard choices and some difficult compromises” from both Israel and Hamas.

The U.S. and the United Kingdom are both staunch allies of Israel, though London diverged from Washington on Monday by suspending some arms exports to Israel because of the risk they could be used to break international law.

The intelligence chiefs’ speech came ahead of a busy week of trans-Atlantic diplomacy that includes a meeting in Washington between Biden and British Prime Minister Keir Starmer. The White House said the talks would touch on Ukraine, Gaza and other issues.

In another sign of the intensification of the “special relationship,” U.S. Secretary of State Antony Blinken will also travel to London early next week for talks with British Foreign Secretary David Lammy and other officials.

The State Department said Blinken would participate in the U.S.-U.K. strategic dialogue on Monday and Tuesday that will cover Ukraine, the Middle East, China and the Indo-Pacific.

In their article, Burns and Moore stressed the strength of the trans-Atlantic relationship in the face of “an unprecedented array of threats,” including an assertive Russia, an ever-more powerful China and the constant drumbeat of international terrorism — all complicated by rapid technological change.

They highlighted Russia’s “reckless campaign of sabotage” across Europe and the “cynical use of technology to spread lies and disinformation designed to drive wedges between us.”

U.S. officials have long accused Moscow of meddling in American elections, and this week the Biden administration seized Kremlin-run websites and charged employees of Russian broadcaster RT with covertly funding social media campaigns to pump out pro-Kremlin messages and sow discord around November’s presidential contest.

Russia has also been linked by Western officials to several planned attacks in Europe, including an alleged plot to burn down Ukrainian-owned businesses in London.

Moore said Russia’s spies were acting in an increasingly desperate and reckless way.

The “Russian intelligence service has gone a bit feral,” he said.

(AP)