Difference there is that those small countries were on the opposite side of the planet and occupied by a native people who have nothing to do with the people who were trying to "liberate" them.
Ukraine is right next door to Russia and a lot of its citizens consider themselves to be Russian. (And for that matter, Ukraine considers them to be Russian as well, which is why it had been ethnically cleansing them.)
How often do small countries beat big countries? I hear you snickering about Afghanistan(twice) and Vietnam.
Difference there is that those small countries were on the opposite side of the planet and occupied by a native people who have nothing to do with the people who were trying to "liberate" them.
Ukraine is right next door to Russia and a lot of its citizens consider themselves to be Russian. (And for that matter, Ukraine considers them to be Russian as well, which is why it had been ethnically cleansing them.)