Belarus is partially controlled by Russia, and could be fully controlled soon. Putin has said that he sees Belarusians, Russians, and Ukrainians as one people.
“Lithuania is calling on NATO to help strengthen its air defenses after a drone carrying 2 kilograms of explosives entered the country from Belarus and crashed in a military training area.”
‘Already in 1993/1994, [Russia] had begun to make threatening language and gestures toward its neighbors. In 1994 the president of Estonia made a speech about how happy Estonia was to be a member of Europe and about the reemergence of a threat from Russia. He was already hearing language from Russia threatening Estonia sovereignty and whether Estonia was really an independent country. At this speech, the deputy mayor of Saint Petersburg, Vladimir Putin, walked out. The language of threat from Russia began in the 90s. In 2005 there was a large cyber attack on Estonia. This is why these countries wanted to join NATO, because they felt a reasonable direct threat from Russia.’
NATO is not a direct threat to Russia’s homeland, and it is only a threat to Russia’s interests if Russia has the intention of dominating its neighbors. Russia’s interest in Ukraine is not primarily defensive, but imperial.
There was almost no U.S. military presence in Eastern Europe until Russia stole Crimea with military force.
Eastern European countries were brought and kept in the Warsaw pact by force. These countries wanted to join NATO because they were afraid Russia would invade them.
Before many of them joined NATO, Russia was already violently intervening in its neighbors.
Poland threatened to develop nuclear weapons to defend itself, and got involved in U.S. politics to push for it joining NATO.