> The occupation of Ukraine signals Russia's intention to do the same with other countries they occupied in the past (Poland, Romania, the Baltic countries, &c)

> The occupation of Ukraine signals Russia's intention to do the same with other countries they occupied in the past (Poland, Romania, the Baltic countries, &c) which are now part of NATO. None of those countries have ever been officially mentioned as the "red line" by Russia, except Ukraine. Article 5 doesn't apply to Ukraine, and it doesn't allow for preventive military measures on non-alliance territories just because "there's a signal" somewhere outside.