When Russia’s Vladimir Putin demanded that the U.S. rule out Ukraine as a future member of the NATO alliance, the U.S. archly replied: NATO has an open-door policy. Any nation, including Ukraine, may apply for membership and be admitted. We’re not changing that.
In the Bucharest declaration of 2008, NATO had put Ukraine and Georgia, ever farther east in the Caucasus, on a path to membership in NATO and coverage under Article 5 of the treaty, which declares that an attack on any one member is an attack on all.
Unable to get a satisfactory answer to his demand, Putin invaded and settled the issue. Neither Ukraine nor Georgia will become members of NATO. Russia resolved that it would go to war to prevent that from happening, just as it did on Thursday.
Putin did exactly what he warned us he would do.
Whatever the character of the Russian president, now being hotly debated here in the USA, he has established his credibility. When Putin warns he will do something, he follows through.