This isn't, "We did this bad and so we can't condemn you now." This is, "We did this over decades, constantly, everywhere, and it was consistently sanctioned and approved." The media smiled and the US people "supported their troops."
You call this a "mistake in the past?" First, the US is still illegally there, taking Iraq's oil, a war crime, as it jumps up and down in moral outrage about this. Second, more importantly, they're not calling a mistake.
The next step for us is to listen to why Russia is concerned with NATO expanding into the Ukraine.
Russia just offered peace under one main circumstance, that the Ukraine declare itself neutral so that there is a buffer zone. Seems reasonable, especially considering that the US already has military bases in 50 countries -- maybe it can skip this one country. Maybe it's up to the Ukraine now.
It doesn't look like you're here to address OP's question, just to push your political views with a throwaway account.
I'm not gonna take the bait, but maybe try Twitter, Reddit, FB, etc. They might be more receptive (at least to arguing with you).
I've been on HN since 2007 but only recently have I been afraid to voice some opinions on my main account.
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.