Ukraine never had any intention to invade Russia. Even if Ukraine joined Nato, do you think other nations would support Ukraine going after Russia ? Nato never had any ambition against Russia. The proof is right here. Nato had the perfect excuse to attack Russia : save ukrain's innocent lives. But even now they do nothing. They have no ambition towards Russia. Russia however have proven time and time again that they like attacking their neirbors. They have also demonstrate the necessity of NATO to defend against Warmongering Russia. Anyone buying into the nato encroching towards Russia speech is buying into Russia's prpaganda. They only give the impression that they are encroching towards Russia because more and more are joining Nato to defend themselves against Putin the warmongerer.
No but they wanted Chrimea back which RU took away from Ukraine. Putin feared that once Ukraine joins NATO, they can start planning to get back Chrimea back with help of NATO or allow close access to American military to Russian borders. Remember American military and missile are deployed in almost every NATO country and RU was against it.
Russia asked US to give full assurance not to make Ukraine part of NATO but Biden said NO and we will consider them making part. So Putin got more pissed by West response i guess.
And i don't think America will ever let Mexico give access to Russian or Chinese military or get them close to American borders. Russia see America as their main Rival, thought of America coming right next to the border is very uncomfortable for them i guess. Also when it comes to invading countries America is ahead of everyone, remember Iraq, Afghanistan and Vietnam? . Both countries got dark history of unwanted military invasions. So they both dont like their borders to be threatened.
That's said Im fully against what RU doing to innocent Ukrainians