Believe me, I remember. I started the Crimea thread on TOS and was comparing it to the annexation of the Sudetenland and was an advocate for any kind of response with real teeth. The push back was "do we really want to go to war with Russia over Crimea" and my retort then, as it is now, is that we wouldn't be going to war over a chunk of land, but showing strength to deter Putin from continuing such actions in the future. Putin openly desires the reformation of the Soviet Union. We should take him seriously. We wouldn't back him down over Crimea, so he is emboldened to take all of Ukraine. We will ask ourselves "do we really want to go to war over Ukraine?" The next line of questions would be about Latvia, Estonia, Albania, Romania, or Poland.
If Putin starts pushing West, the answer should always be to push back. The world cannot afford an emboldened Vladimir Putin, as Putin in his current form is beholden only to a collective of Oligarchs. As long has he keeps the right people within Russia happy, he has carte blanche with the rest of the world.