NATO, the United States and the E.U. are now planning for the long-term isolation of Russia, marking the return of Cold War-style containment after years of coexistence and cooperation.

“This is one of those moments in European history,” said Alexander Stubb, Finland’s former prime minister. “What we are looking at is the semi-permanent division of Europe into two.”

On one side, he said, you have an aggressive, authoritarian Russia and its cobelligerent, Belarus. On the other, you have more than 30 democracies more or less united by a common foe.

“It will all be one military-strategic arena now, especially if you look from the Russian side,” said Anna Wieslander, director for Northern Europe at the Atlantic Council.