More information can be found in this position statement from the Department of State:
Taiwan is hurt indirectly. Taiwan has invested heavily on the mainland China and manufactures there.
Many Chinese products exported to US have very low Chinese value added. Chinese manufacturer buys Taiwanese, Japanese or US made components, assembles them and sell them to the US.
For many high-tech products, Chinese value added may be just 20% of the price of the product. Chinese tariffs hit everyone in the value chain. Even the US.
That is not strightly true because there isn't really an alternative to Foxconn in size and scale. But in other industry where there are lots of alternative around the world, the heat are quite intense.
The mainland Chinese government disagrees.
I don't know about these particular tariffs, but I believe the U.S. would not consider tariffs aimed at (mainland) China to apply to Taiwan.
That's a minority/extremity opinion which isn't remotely prevalent even among those who feel intimate with China. It used to be the 'political-correct' belief held by the former authoritarian ruling party. But it's not considered a rational worldview anymore after its democratic modernization.
There are things that are de facto true, even if they're not de jure true.
The status of Taiwan is one. Israel's nuclear status is another famous example.
While the common sense reaction is "everybody knows it, why pretend?" those fictions generally exist because they help maintain delicate balances and order between parties that are generally at odds with one another.
What it comes down to is that it'd be lovely if we could all just say openly and outright that mainland China and Taiwan are separate entities, because, in practice, they are. But it's also pretty swimming for the global community for the PPRC and ROC to both claim that they're the real China while everyone does business with each other anyway. So while it's true that they're distinct and it's also true that everyone knows that to be the case, everyone also wins out to varying degrees by officially pretending that it isn't the case.
Heh. Exactly how close an ally is yet to be tested in any meaningful way. No U.S. aircraft carrier group has transited the Taiwan Strait since 2007. Some would forecast that no U.S. carrier group will transit - or finish transiting - that strait ever again.
China may be able to force import tariffs on goods imported by Taiwan (idk not an expert) but I bet Taiwan imports relatively little directly from the US?
Other nations play pretend to various degrees, trying to placate (mainland) China without too much swallowing their own pride in not being China's lapdogs. But they're effectively two separate countries.
So: The tariffs being applied to China do not apply to Taiwan. However, Trump seems to be throwing tariffs at several targets lately; he may or may not have applied some to Taiwan.
Sometimes you wonder how things can stay broken for so long.
Taiwan doesn't want the mainland's government, and the mainland doesn't want Taiwan's government.
If Hong Kong had been militarily defensible, it'd be in the same situation.
If the UK had really wanted to keep Hong Kong, could it have militarily defended it? No doubt the geography is less than favourable; but, keeping in mind that UK and PRC are nuclear powers, would regaining Hong Kong be worth the risk of war between two nuclear states? PRC might well have decided it wasn't worth that risk.
But in reality, the UK had no real interest in keeping Hong Kong, and were more than happy to hand it over to PRC. (Yes, there was a treaty saying they had to give back a big chunk after 99 years, but if the UK really wanted to get out of that, they could have found a solution – e.g. if they hadn't switched recognition from ROC to PRC, they could have asked ROC for a lease extension. Or, they could have made their switch of recognition from ROC to PRC conditional on PRC granting them perpetual sovereignty over the whole of Hong Kong.)
The Chinese would not have to have fired a shot to make HK surrender. HK was then a city with more than 6 million citizens, which was entirely dependent on water imported from the mainland. The treaty that allowed the importation of all that water was only set until the end of the lease, and the Chinese very clearly stated that they had no interest in extending it.
Also, earlier when HK expressed some interest in investing into desalinization, the Chinese threatened to immediately cut off the water supply if it seemed like the HK local government would have actually tried to build up enough water resources to make them not dependent on the mainland.
The result of shutting down the taps would have been millions dead within a week. Keeping HK British would have required a massive invasion of China by the UK, just to secure water. I don't see that as very likely.
Hong Kong also had its own desalination plant 1975-1981. Why was it shut down – because of pressure from the PRC government? Or because it was significantly more expensive than importing water? I don't know for sure, but my impression is the later was a much bigger factor than the former.
If the UK had thought this through, they would have setup real democracy in Hong Kong a generation before the lease ended, instead of doing the colonial "high commissioner" thing. A legitimate Hong Kong government would have survived a lot longer with their people's support.
A democratic HK would squarely falsify this claim.
Indeed, I'd argue that the single most urgent reason (but not the only one) for China 's bullying of Taiwan is precisely this, Taiwan is a thriving democratic and Chinese society.
But if the UK had done the same thing in 1980 or 1970 or 1960 or 1950? I don't think the PRC could have done anything about it.
The UK never really cared about Hong Kong democracy. If they had, they would have implemented democratic reforms decades ago, instead of leaving it until the very last minute.
Both for their colonies and for themselves.