West will exert ‘unrelenting’ pressure to ensure Vladimir Putin’s aggression fails, says Boris Johnson

The west is ready to maintain “unrelenting” diplomatic and economic pressure over the long term to ensure the failure of Vladimir Putin’s imperial ambitions, even if the Russian president succeeds in his immediate goal of overrunning Kyiv and seizing parts of Ukraine, Boris Johnson has vowed.

In some of his gloomiest comments since the start of Russia’s unprovoked invasion of its neighbour on Thursday, the prime minister said Putin appeared intent on unleashing indiscriminate firepower against Kyiv as he did on Grozny, which was razed to the ground in the 2000 Chechen war.

The world was faced by a struggle between “good and evil” in Ukraine, and Russians involved in atrocities should be aware they will face prosecution in the international courts for war crimes, he said.

But Mr Johnson insisted that a successful Russian seizure of part of the country would result only in a “prolonged crisis”, with guerrilla warfare from Ukrainian resistance backed by crippling economic sanctions from the international community.

Speaking during a one-day visit to frontline Nato states Poland and Estonia, the prime minister warned Putin that any attempt to hold Ukraine over the long term will be “militarily exhausting and economically ruinous” for Russia.

And he urged the Russian president: “There is only one way out of this morass and that is to stop the tanks, to turn back the tanks on their way to Kyiv, turn them round and take the path of peace.”

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With a 40km-long convoy of armoured Russian vehicles approaching the Ukrainian capital, Mr Johnson’s comments indicated that he expects Putin to respond to the frustration of his hopes for swift victory by stepping up the scale of violence inflicted by his troops.

Putin has been forced into a “cul-de-sac” by the unexpectedly tenacious resistance offered by Ukraine’s army and people, said Mr Johnson.

And he has already demonstrated his readiness to resort to atrocity with a rocket attack on residential areas and on Freedom Square in the heart of the country’s second city Kharkiv.

“If you’re sitting where he is, his only instinct is going to be to double down and to try and ‘Grozny-fy’ Kyiv and to reduce it to [rubble] ,” Mr Johnson told ITV News.

“I think that that would be an unalterable moral humanitarian catastrophe and I hope he doesn’t do that. I hope he has the wisdom to see that there must be a better way forward.”

This map shows the extent of Russia’s attack on Ukraine (PA)

In a speech in Warsaw following talks with Polish PM Mateusz Morawiecki, Mr Johnson warned that Putin’s “imperial ambitions” do not stop at the Ukrainian border.

“Putin’s aim is to overthrow the post-Cold War order and destroy the vision of a Europe whole and free,” he said.

If the Russian president succeeds in taking Ukraine, “the outcome would be a world where aggression has triumphed, where might is right and extreme violence pays off and no nation would be safe”.

He made clear that this meant the west and its international allies being prepared for a protracted struggle to ensure the ultimate failure of Putin’s aggression.

Participants in the Standing in Solidarity with Ukraine vigil in Edinburgh on Tuesday (PA)

“If the worst happens, and president [Volodymyr] Zelensky’s government is no longer able to function in Kyiv, we must prepare to support them whatever happens in the weeks ahead,” said the prime minister.

He acknowledged that this will impose costs on the British people and their allies in terms of rising energy prices and that in the longer term Europe will have to wean itself off Russian oil and gas.

✕ Boris: Putin ‘fatally underestimated’ resolve of Ukraine

But he said: “If we are to have any chance of ending this nightmare, then Putin must understand that his savagery will be met with unrelenting economic pressure and that the west will be united in supporting Ukraine and that we are ready for a prolonged crisis.

“I have no doubt that if the west can maintain the extraordinary unity we have shown so far, if we can press ahead with the strategy we have set out – of international economic, humanitarian, and diplomatic assistance to Ukraine, along with defensive weapons – then Putin’s venture will ultimately fail.”

At a press confernce following talks with Nato secretary general Jens Stoltenberg at a UK military base in Estonia, Mr Johnson was confronted by a Ukrainian anti-corruption campaigner who called on him to comply with president Zelensky’s request for a no-fly zone.

Daria Kaleniuk told him: “Ukrainian women and Ukrainian children are in deep fear because of bombs and missiles which are going from the sky. Ukrainian people are desperately asking for the rights to protect our sky, we are asking for a no-fly zone.

“What’s the alternative for the no-fly zone?

✕ ‘You are not coming to Lviv because you are afraid!’ Ukrainian woman breaks down during Boris press conference

“Nato is not willing to defend because Nato is afraid of World War Three but it’s already started and it’s Ukrainian children who are there taking the hit.”

But Mr Johnson responded: “Unfortunately the implication of that is the UK would be engaged in shooting down Russian planes, it would be engaged in direct combat with Russia.

“That’s not something that we can do or that we’ve envisaged. The consequences of that would be truly very, very difficult to control.”