I think you're using the term liberal to mean too many things and also nothing at all. You're crafting a bogeyman. The things you've said suggest liberal means the liberal ideology, democratic politicians, liberal voters, western governments, social democrats and really anyone who isn't a marxist. They're not the same thing. Genuine opposition also doesn't mean anything, if someone criticizes their government but doesn't go as far as you believe then suddenly their position is loyalty to a state, insufficiently anti-imperialist or basically a fake. That's moving a goal post or a strawman or something, I dunno but it is disingenuous.
If genuine opposition means adopting your personal belief of a solution then you're saying genuine opposition is an agreement with your politics. Someone can oppose all those things without arriving at the same conclusion as you. You can't just decide what is a genuine opposition because it doesn't go far enough for you.
I also think it's pretty hypocritical the way you speak of Ukraine. The 2013/2014 events as a western backed coup is just not true. There was an enormous domestic protest of hundreds of thousands, a lot of which died during their protests because of a state crackdown lead by Yanukovych. When they kept pushing he literally fled the country TO RUSSIA where he is now hanging out with bashar al assad probably at some swanky resort because he's never been anything but a Russian puppet. Now you can criticize Ukraine on how it used its procedures to remove Yanukovych and maybe that was questionable. You can debate the west or the EU had strategic investments in Ukraine, sure. But calling it a western led coup delegitimizes the sovereignty of Ukrainians who ultimately decide how the hell their government should and will function.
Which is extremely relevant to your argument about liberals. You're suggesting they don't genuinely oppose their government because their opposition doesn't result in change of the state. But when Ukraine does, you're inclined to interpret their actions as if it was solely a foreign power than the agency of it's citizens.
I see this all the time with marxist, socialist, etc folk here on Lemmy. Their analysis of the United States in comparison to China or Russia is lopsided. Russia has its own ruling elite and imperial interests, as does China and North Korea. Russia invaded Ukraine like assholes because Ukraine didn't do what it wanted. China has engaged in coercive territorial disputes with neighboring states and has been accused with really strong evidence of operating overseas citizen policing centers as part of transnational repression.
The biggest thing I want to make clear when I'm talking about liberals, I mean people broadly committed to liberal traditions of individual liberty, democratic government, civil liberties. Recognizing that liberal democracies provide citizens with substantially greater autonomy and political rights than authoritariajn states is not the same thing as being loyal to the state. These people likely realize democratic institutions and civil liberties are preferable to authoritarian alternatives like you find in Russia, China, North Korea.
Ordinary Americans have virtually no input on any foreign policy decision, not has US foreign policy ever been about serving the interests of ordinary Americans.
Democracy creates mechanisms which ordinary people can influence state policy even if those mechanisms are imperfect. At least in this country we have them and we understand why they're failing, because wealthy individuals, many of which aren't native to this country or even live here, have spent a lot of money encouraging a culture of Americans to not vote, not believe in democracy and allow them to continue to descend into an authoritarian state. China, Russia and North Korea don't have that and Trump wishes the United States didn't have that. Which is partly why Trump is depicted on that side of the seewsaw, because he wants to be on that side acting as those countries you're heavily less critical of, act.