LONDON: The mass international expulsion of Russian diplomats over the poisoning of a former double agent in Britain represents a key diplomatic victory for Prime Minister Theresa May despite Brexit tensions with London's EU partners, commentators said.
Foreign Secretary Boris Johnson, a leading Brexit advocate, hailed an "extraordinary international response", while May said it showed "great solidarity" with the EU and NATO.
"Together we have sent a message that we will not tolerate Russia's continued attempts to flout international law and undermine our values," May told parliament.
"As a sovereign European democracy, the United Kingdom will stand shoulder to shoulder with the EU and with NATO to face down these threats together," she said.
Washington led the way, ordering out 60 alleged Russian agents.
Sixteen European Union countries have so far matched the move with smaller-scale expulsions, after Britain urged allies to respond to the poisoning of double agent Sergei Skripal and his daughter Yulia and expelled 23 Russian diplomats.
At an EU summit last week May persuaded member states to agree with Britain's assessment that it was "highly likely" Moscow was to blame for the nerve agent poisoning of Sergei Skripal and his daughter Yulia in the English city of Salisbury.
EU leaders at the summit also agreed to recall the bloc's ambassador from Moscow over the March 4 incident.
After the summit, EU President Donald Tusk told a press conference: "In these difficult circumstances I am personally especially pleased that despite the tough Brexit negotiations, the European Union has demonstrated unanimous and unequivocal unity with the UK in the face of this attack."
Russia on Monday accused Britain of "exploiting the factor of solidarity" within Europe and imposing worsening relations on other countries.
"When London withdraws from the EU, it will not be bound by any obligations within the framework of the single foreign policy line," said foreign ministry spokeswoman Maria Zakharova.
"Depending on its wishes, it can start a game of either rapprochement or growing further apart, while the countries that will remain in the EU will continue to be bound by the conspiracy of anti-Russian solidarity imposed by the British," she added.
- 'This is just geopolitics' -
Before the Skripal poisoning, May last month had pleaded for an urgent deal with the European Union on post-Brexit security cooperation in a speech at the Munich Security Conference.
"This cannot be a time when any of us allow competition between partners, rigid institutional restrictions or deep-seated ideology to inhibit our cooperation and jeopardise the security of our citizens," May told the audience.
Jan Techau, a Berlin-based analyst for the German Marshall Fund of the United States, said Monday's response presaged continued cooperation on common security and defence concerns whatever the status of Brexit negotiations.
"Since immediately after the Brexit vote, it has been made clear again and again by both the UK and the EU that security would still be considered a shared concern and that both sides would coordinate and cooperate very closely," he said.
Anand Menon, European politics professor at King's College London, agreed that the response did not depend on Brexit.
"Whether we have Brexit, whether we don't have Brexit, Russia has been shown to have used aggression on the territory of a member state and member states react."
"I don't think it's got anything to do with Brexit... This is just geopolitics," he said.
Brexit supporters seized on the response as evidence that Britain's foreign policy clout would not be affected.
The political blog Guido Fawkes said the expulsions were "one of the biggest wins of the May premiership" and made "a mockery of those claims the UK would be isolated internationally if we voted to leave the EU".