It’s not quite as imbalanced as it looks on paper — Russia may have a “3 million man army,” BUT…
—That’s 1 million active-duty, 2 million reservists. And many of those are needed to guard the rest of Russia’s extensive territory.
—Only 150,000 or so were deployed to the border with Ukraine. Most of those have now crossed the border, but not all.
—America, the E.U., and even countries as far away as Australia have pledged military and financial aid to Ukraine. Russia has no active allies other than Belarus and is pretty much on its own.
Ukraine has 40+ million citizens, and many of them are taking up arms despite having never enlisted before. Some Ukrainian expatriates are actually returning to Ukraine to fight. Ukrainians are fighting for their freedom. On the Russian side, many know that the war is bullshit.
Russia has the ability to nuke all of Ukraine to a pile of radioactive ash or simply shell all the cities to rubble, but what will Russia have gained at that point? Russia of all countries hardly needs more territory. What Putin would like is Ukrainians to passively accept his rule, but it doesn’t look like that’s happening.