From a New York Times essay by Richard N. Haass headlined “The West Must Show Putin How Wrong He Is to Choose War”:

The moment, after a standoff stretching for months, has arrived. Russia’s invasion of Ukraine is underway.

On Wednesday, President Vladimir Putin said that he has decided to carry out a “special military operation” in eastern Ukraine. Earlier this week, he had ordered his military into two regions in eastern Ukraine, giving the lie to the claim — often repeated by Russian officials — that he had no intention of invading. As well as an act of aggression, it’s a blatant violation of the basic legal principle that international borders are not to be changed by force and that sovereign countries are free to make their own decisions.