> My argument is that Russia was compelled to attack both Georgia and Ukraine because of NATO expansion, or rather preventing NATO expansion, not because of "Putin is crazy, wants to be a Tsar".

This fails to explain why Russia attacked both countries after NATO had decided not to offer them a path to membership.

Putin's intense hostility toward NATO stems from the fact that NATO stands in the way of invading Europe. The blitzkrieg against Ukraine also failed largely because of military support from European NATO members, who used established NATO communication channels to coordinate their efforts - exactly the thing NATO was established for!

If Russia were a normal European country, it would have nothing to lose and much to gain from bordering NATO. NATO membership comes with oversight and separation requirements that make member states stable and predictable. A former, pre-Putin foreign minister of Russia described this as "free-of-charge security on Russia's western border".

It is a problem for Putin only because he seeks to invade Europe; NATO stands in the way.

  > Your argument is that Russia wants to occupy territory just for the sake of expanding Russia, which is really not logical or reasonable.

It is perfectly reasonable when you look at who holds power in Russia: the old revanchist KGB clan seeking to restore the USSR and the Eastern Bloc. This is the world they grew up in and were indoctrinated into in KGB schools. For them, it is a "normalcy" to which they must return.

  > My argument is that if Mexico or Canada joined a military pact with Russia, the US would invade those countries immediately.

There is no need for guessing games when Cuba was actually in a military pact with the USSR until 1991 and hosted jets, bombers, missile cruisers and other conventional weapons for decades after the missile crisis. You can read about Soviet warships conducting missile drills off the coast of Florida in old newspapers. This is far more than anyone has done for countries that have joined NATO since the end of the Cold War. And yet, the US did not invade Cuba.

  > Your argument is that any country can join a mutually defence pact without any consequences, as should be the case for Ukraine.

Russia has repeatedly, in writing, pledged to respect the sovereignty of other European countries, including Ukraine, and their freedom to join military alliances. There's nothing to discuss - unless you want to turn Europe into a landscape of semi-sovereign nations ruled by Russia, which raises the question: why should Russia, in particular, be the European master race? Shouldn't the Franco-German alliance, with its much larger economy, bigger population, and numerous allies, instead dictate what Russia can and cannot do?