KYIV, Ukraine — When the British destroyer H.M.S. Defender sailed near the coast of Crimea on Wednesday, it was supposed to be quietly demonstrating that the waters legally belonged to Ukraine despite Russia’s annexation of the Black Sea peninsula seven years ago, which has never been recognized internationally.
To Russia, however, which claims those waters as part of its territory, the ship’s course was an intolerable provocation.
The conflicting narratives erupted into an international incident after the Russian Navy claimed it had fired warning shots at the British destroyer and dropped bombs in an effort to make it alter course. The British government promptly denied both claims, and said that the Russians had merely been conducting naval exercises nearby.
And things might have ended there, except that a BBC correspondent, Jonathan Beale, happened to be on board the Defender and published video footage showing as many as 20 Russian warplanes buzzing the ship and a Russian Coast Guard vessel drawing close alongside.
A Russian officer could be heard on the radio threatening to open fire if the Defender did not change course, while gunfire could be heard in the background, though the shots seemed well out of range.
In an interview with the BBC, the Defender’s captain, Cmdr. Vince Owen, made it clear that the ship deliberately sailed close to the Crimean coast to assert the position that Crimea and the waters around it legally belong to Ukraine.
“With the U.K. and the Royal Navy, our deployment is here to maintain international order, and uphold that for the global peace and security,” Commander Owen told the BBC.
“The Royal Navy and U.K. will always call out states that do not follow international order,” he added. “That’s our mission.”
Russia’s 2014 annexation of Ukraine prompted international outcry and economic sanctions. In the seven intervening years, the Black Sea has become a flash point for Ukraine, Russia and NATO member countries.
“Politically, the Russians are enormously sensitive when it comes to Crimea,” said Gustav Gressel, a senior policy fellow at the European Council on Foreign Relations. “They want to bully the West into de facto recognizing Crimea and turning the page.”
That is why Britain and the West “precisely need to keep reaffirming and reminding that Crimea has not been accepted as a fait accompli,” said Mark Galeotti, a Russia expert at the University College London’s School of Slavonic and Eastern European Studies.
In a foreign and defense policy review this year, Britain called Russia its most acute and direct threat, something that Ben Wallace, the defense secretary, reasserted on Wednesday.
“Russia’s activity is a threat to stability, and we all need stability to have security,” he said to lawmakers.
Prime Minister Boris Johnson told reporters on Thursday that Britain did not recognize Russia’s annexation of Crimea and that it had been entirely appropriate for the vessel to traverse Ukrainian waters in accordance with the law.
Mr. Galeotti said the exercise revealed “a post-Brexit British determination to affirm that if America is back, so too is Britain, in its own way,” referring to President Biden’s refrain during his recent trip to Europe.
But there was also a sense that Russia was “working to isolate Britain and aggravate that post-Brexit decision,” said Nigel Gould-Davies, senior fellow for Russia and Eurasia at the International Institute for Strategic Studies in London.
In Moscow, Russian officials doubled down on their version of events and warned that the country’s military would be ready to take decisive action should such events occur in the future.
Speaking to reporters on Thursday, the Kremlin’s spokesman, Dmitri S. Peskov, called the British ship’s actions “a deliberate and premeditated provocation” and added that “no options will be ruled out in terms of legally defending Russia’s borders” in the future.
Sergei Ryabkov, Russia’s deputy foreign minister, was more specific, saying on Thursday that next time Russia “may drop bombs and not just in the path but right on target.”
“Those who try to test our strength are taking high risks,” Mr. Ryabkov said, according to Interfax, a Russian news agency, and suggested Britain rename the destroyer H.M.S. “Aggressor.”
Mr. Ryabkov’s remarks represented a rhetorical escalation, Mr. Galeotti said. “It is very hard to crank these things down,” he said. “Next time — and there will be a next time — will the Russians feel they have to be more bullish?”
Even as the confrontation unfolded on Wednesday, France and Germany proposed that the European Union hold a summit with Russia to work on thawing relations, the first such meeting since 2014. The suggestion was met with dismay from leaders of some E.U. member states, including Lithuania’s foreign minister, Gabrielius Landsbergis, who told the Financial Times it was an “irresponsible” case of “historic myopia.”
In several days, the Black Sea will be the site of the Sea Breeze military exercise, a land, sea and air training operation hosted by the United States and Ukraine with the participation of 30 other countries.
Valerie Hopkins reported from Kyiv, Ukraine, Ivan Nechepurenko from Moscow and Isabella Kwai from London.