I've been thinking a bit about this. So technically the UN would be the world authority that would facilitate international voting and decide when an invasion is legitimate and when it's tyrannical, right? So back in 2003 when the UN voted no to the invasion of Iraq and the coalition still did it, shouldn't sanctions be applied in the same way?
I know the international community criticized it and many Americans and citizens from other countries protested against it but nothing really happen for the average American (assuming they had no relation to the industrial-military complex) but still, the war still happened and lasted many years.
Who decides which invasion is legitimate and which isn't? At what point should we as citizens start pressuring others to apply sanctions?
I'm also wondering this because recently a Canadian dude posted something on my country's subreddit and said he was disappointed at my country not sanctioning Russia (my country never has done anything like that) and later Americans also got in there and called us cowards.
So far it seems that it depends what the most powerful countries say and if they have a good propaganda machine or not but I don't know... it's such a bleak scenario.
I'm not saying Russia is doing good or anything, just wondering why some conflicts get more backlash than others.