Ukraine turned to NATO because Russia had already invaded them, occupying Crimea and eastern parts of the country. That invasion was completely unjustified as well. It started with Russia getting a big mad Ukraine was acting like a sovereign nation and wanted to sign a free trade agreement with a functional economy instead of them.

Russia's problems are all of their own making. They had no need to invade Ukraine. They did so because Ukraine didn't want to be their puppet state like Belarus. The Russian government wants to treat former SSRs like they're still economic tributaries to Moscow.