Taiwan isn't a former vassal state, it was and, according to both the PRC and ROC, still is, a part of a single unified china. Taiwan (the republic of china) still lays claim to mainland china, and in fact iirc to land outside of PRC territory that the PRC conceded between the end of the civil war and today. So that's one difference.

More importantly though, China isn't currently blockading taiwan and threatening to kidnap their politicians or send in ground troops. Like, even if you think Cuba and Taiwan are exactly the same... The actual situation is, clearly, vastly different. Taiwan is one of the SEA tigers because China hasn't been waging economic warfare against them. Cuba is extremely poor because America has. Taiwan isn't currently undergoing rolling blackouts and an inability to respond to medical and other emergencies due to a worrying heightening of Chinese economic warfare against them. Cuba is. Xi Jinping has not said that he intends to kidnap senior figures within Taiwan. Trump has in fact said that about Cuban figures. Xi Jinping has also not threatened to invade Taiwan complete with moving forces into the region. Trump has done those things. I doubt many people here would be happy about china immiserating the Taiwanese people, destroying their economy, or threatening to remove their leaders and invade them militarily, but those things are not happening, even if you think it's only a matter of time before the big spoopy socialists do all of those things... They still aren't, and there's no really good reason to think they plan to.

We aren't complaining about the actions China is taking against Taiwan because, well, they aren't. If I am wrong I would love to hear what actual, provable, aggressive or violent actions China has taken against Taiwan that are even vaguely comparable to the American confrontation with Cuba. Until then you are just punching left because you take lazy propaganda from literal fascists at face value.

Imperialism is when one faction in a civil war takes territory from another faction

What part of the Chinese civil war was imperialism?

Imperialism is imperialism.

The union invading the confederacy was such terrible imperialism.

Words have meanings you know.

England should invade the US it would be funny

"Oh, so the allies were right to invade France then? Imperialism is imperialism."

You realize it was the "Taiwanese" who invaded Formosa after they lost the civil war and slaughtered the indigenous natives there right? Getting rid of the Taiwanese government is an act of decolonization, not colonization. Taiwan is a colonial outpost

Yes the Brits do have a right, and a duty, to invade and depose the so-called "US" secessionist regime due to their genocide of the native population and global wars of aggression.

The PRC government has consistently said they have no plans to invade Taiwan and wants to incentivize them to return to the fold through diplomatic and economic means, even if it takes 100 years. Invasion is a last resort if the United States decides to turn Taiwan into a missile platform from which to attack China.

Imperialism is when a Rogue Province separated by fascist nationalists who refused to accept their defeat in the civil war, and turned the Island into a settler-colony by ethnically cleansing the indigenous population, and a US military outpost a few miles away from China, gets reunited with the rest of the country.