I think what SR is getting at is the reasoning that has been given for the invasion is being questioned. And, it's not just the political left. It's the news organizations that deliver the news, the same ones that were piling on and shedding any semblance of unbiased reporting during the Trump administration. Doing so sewed a lot of distrust and now that distrust is coming up.
That said, the most basic facts that I can see is a nation violated the sovereignty of another nation without a casus belli. That, alone, makes Russia the aggressor and must be stopped.
You also asked several pages ago what we who believe Biden isn't doing enough think should be done. First, armed US drones should have been flying over Ukraine airspace since December. Second them to the Ukrainian military. Heck, second the drone pilots to the Ukrainian military and slap a Ukrainian flag on the drones. Then, the first time a Russian tank or vehicle crossed the border, it should have been lit up.
Second, send special forces into the Ukraine to act as advisors for resistance fighting. In fact,
this would be an extension of what they were already doing with the regular military (and I recognize this very well may be happening and kept secret).
Third, create in Russia what the
Soviet Union created in the United States during the Vietnam war. Pour millions of dollars into funding peace movements, student agitators, and the like. And then, when they get arrested, make sure that information spreads as well.
Those are three things just off the top of my head, none of which would put the foot of a US solder wearing a US flag in combat.