Every country in history has made mistakes and perpetuated violence against their neighbors or fellow countrymen at some point in history. But I don't think it's a sign of progress to say "this bad thing happened 20 years ago or 200 years ago or 1,000 years ago, so I should be OK with it now." It's OK to make a bad decision in the past and a better decision today.
Plus, no two countries, wars, circumstances, etc. are exactly the same. Comparing Ukraine to Iraq is missing the differences in the geopolitical, economic, cultural and ethnic state of affairs in the two scenarios.