No, we didn’t stop the war. I marched with 300k people in Washington (a lot of veterans) and we still didn’t stop the war. But I think the widespread and global protests of the Iraq war made it clear that the US was going to wage war despite its unpopularity, evidence, allies backing out, etc. A similar thing appears to be happening now with the backlash to Israel’s Hamas response.

Here’s a good column about what those protests writ large “accomplished.” https://www.commondreams.org/opinion/20-year-anniversary-of-iraq-war-protests