Earlier quoted context omitted.
In the modern world, no country is self-sufficient. This isn't even an accident, it's an explicit goal of the modern liberal economic system, partly to try to dampen the conditions that lead to war. At any rate, sanctions create consequences for trade for third parties as well, so any country that doesn't come along on it will also face the possibility of being shut off from trade with the EU, the US, and the rest of…
We aren't trading with people conducting war isn't the same as going to war. It just isn't. It is their choice to invade, enabling their invasion through trade would be closer to war than sanctions.
In the US' case, sanctions often also come with things like "withholding the target country's reserves held with the US central bank", which do material harm to the target country's economy.
People keep trying to frame this as "just not buying gas/oil" but the funniest thing about that is that for the most part, the sanctioning countries are still buying gas from russia. That is literally the one thing not included in these sanctions. The sanctions would probably work better if they did stop buying natural resources, but the backsplash from doing that would be immense.
Anyways, it's awfully convenient that the tools America is uniquely positioned to use to cause harm to other countries (economic sanctions, targeted drone strikes, etc) are never "cause for war."
And again, this is completely independent of whether or not it's the right thing to do. If you can't get over your cognitive dissonance long enough to recognize that sometimes the right thing to do can cause immense harm, I don't know what to tell you. You should still recognize that sanctions are not neutral acts, and they do kill people as surely as a gun does. Thinking otherwise means you're somehow still stuck in the 19th century's idea of war (and even they would probably consider a trade blockade an act of war).