Ukrainians look across the fence at Poland and see folks making 5 times their income. Being Russia's vassal doesn't cut it.

Putin is a short shit. To most folks that's not a big deal, just a fact of life. Like being good at math, or having hazel eyes. To Putin, with his inferiority complex, it's an obligation to do macho stuff. Riding horses bare-chested, ditching dowdy looking wife, displaying the regalia of the Tzars, seizing Crimea, etc. To quote a Russian female commentator "He's a small man!"

NATO has not been any danger to Russia. Russia's been a danger to its neighbors.