I think the US-Canada relationship is a *bit* different than Russian-Ukrainian history. the canadian cossacks weren't given protection by the US as the cossacks tried to get out of the grips of another empire (the poles). the concept of "Ukraine" more than predates what Putin decided was history (he claimed Lenin invented it) considering Russia banned the study of Ukrainian language in the 18th century as they attempted to Russify the area. during the Russian civil war, Ukraine ended up parceled up between Bolsheviks and the poles, but Lenin didn't invent the concept of Ukraine. Ukraine has been trying to be independent for hundreds of years. yes, they've been under multiple different spheres of influence, most recently the Bolsheviks, and they are trying to stay out of russian sphere. Yes, spheres of influence exist, i've played plenty of Victoria II sphering nations. but it isn't part of Russia, and Ukraine wasn't actually in its sphere after the fall of the USSR. russia was trying to sphere it (eg, Yanukovych), supporting various pro-russian government entities and when the people had enough of their machinations of foreign meddling the russians flipped the table. Ukraine has amended its constitution to state it wants closer ties with EU and NATO. Putin has unilaterally decided that this means Ukraine isn't a real country.
even in western ukraine overwhelming majorities did not support remaining with russia in the vote for independence; over 90% of the Ukrainians wanted independent Ukraine. only in crimea, because of Svastapol, was there great amount of support to stay with Russia (but still a minority). Ukraine voted for independence before the fall of the USSR. it was one of the final things that happened before the USSR collapsed, but I don't think that means it's because of political machinations within Russia and discounting the protests and the supreme soviet declaring independence even before the people voted for it