A defeat for Ukraine would usher in a new era of fear in the whole Euro-Atlantic area, as Putin continues his drive to rebuild the Soviet empire, writes Boris Johnson.
"It will be a turning point in history, the moment when the West finally loses its post-war hegemony, the moment when borders everywhere are suddenly up for grabs and aggression is seen to pay — and all because of a failure to stand up for Ukraine."
Culture and sport bodies should continue to "exile Putin's Russia from their ranks", a minister says.
UK ministers are meeting international allies to "ratchet up the pressure" on Vladimir Putin by taking more sporting, cultural and economic steps in the wake of Russia's invasion of Ukraine.
The culture secretary will try to mobilise more support to isolate Moscow at a summit of global sports ministers.
Nadine Dorries said culture was "the third front in the Ukrainian war".