“We’ve got a couple different signaling audiences.
There’s Chinese domestic politics. National Day was October 1. It’s often a day for the Chinese government to emphasize their nationalist credentials and project hope for the future about reunifying China, whether that means Taiwan or suppressing the Uyghurs or that kind of thing.
There’s a Taiwanese politics component, specifically an attempt to demoralize the public that China is stronger and you can’t win. The quote-unquote pragmatic choice is just to unify with us. Those tend to backfire. In 1996, China launched a couple missiles across the Taiwan Strait. It ended up — there was an election in Taiwan at the time — boosting the less pro-China candidate. And recently, with the protests and the crackdown in Hong Kong, going into this most recent election the current president, Tsai Ing-wen [of the pro-Taiwan independence Democratic Progressive Party, or DPP], was looking a little bit shaky, especially among youth. But when all that happened in Hong Kong, it was like, “Nope, we don’t want this to happen to Taiwan.”
It also feeds into Taiwanese party politics. The Kuomintang Party [Taiwan’s other major political party, which favors closer ties with mainland China] talking point is to say things like, “Well, the DPP can’t stabilize Taiwanese-Chinese relations. This is clearly an example of that — look at China’s belligerence, we’re better caretakers of the cross-strait relations.”
Then there’s international politics. The US, the UK, and four other countries are doing military exercises in the East Philippine Sea. So it’s partly as a demonstration of, “Stay out, we have a dog in this fight as well, we have the ability to strike too.””
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“I think recently — not just this October, but the previous few months — has been a response to the broader tightening of US alliances in the region. The Joe Biden administration has, kind of surprisingly to me, quickly coalesced a coalition against China and tightened those alliance relationships that have been atrophying a bit under the Trump administration.
A lot of the countries in the region — Japan, South Korea, Philippines probably — they look at Taiwan as a litmus test for US commitment and Chinese assertiveness, which just puts China’s back up.”
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“the US has a really tricky job here. It has to reassure Taiwan and take the lead in solidifying this coalition, but it has to do so in such a way that China doesn’t think “better strike now, or else we’re going to lose this thing forever.” And then the US has to kind of moderate its own policies toward China so it doesn’t jumpstart a war on its own for some other issue area, like the South China Sea. It’s a really tricky balancing act.”
https://www.vox.com/22713517/china-taiwan-tensions-united-states-xi-biden