I don't think Biden is stupid (much less 'senile') but it would take a remarkable effort to make a difference to American society and the heading it is on in terms of e.g. lunatics in the GOP becoming even more rabid. And in terms of the challenges presented by global climate change. I don't even mean he is 'shirking' what needs to be done, if it is even possible from his position and resources. I just think this pact doesn't address the real problems, and I don't like our rulers putting us in a confrontational position. In fact the US/UK establishment often behave so shortsightedly (that's one description) it doesn't give me a good feeling. What's the logical next step: China gives in, 'gets the message' and backs away? If not, then what?
It's a reactive measure, not a proactive measure.
There was little reaction to China claiming the South China Sea and militarising Islands there back in the Obama era. This was seen by the Chinese Communist Party as evidence that the balance of power had shifted and that the US order was in decline. Hong Kong's autonomy being cut short should be seen in this light.
China is also very serious about invading Taiwan and there are good reasons to believe Xi wants it to be his legacy - which means he could try within the next decade. The risk here is that a lot of the more hawkish elements of the PLA and CCP believe that American society is weak and will not stomach casualties or a war over Taiwan, and that a sudden devastating attack on US navy in the region accompanying an invasion of Taiwan would see the US retreat and give the PLA Navy total hegemony over the Pacific and South China Sea.
This is one example of the sort of rhetoric which is thrown around:
They’re the pride of the US fleet: enormous 100,000 tonne, 333m long nuclear-powered aircraft carriers. But Beijing thinks they’re Washington’s achilles heel.
www.news.com.au
It is also worth pointing out that, while China's navy is untested, it isn't unimaginable that they could be capable of driving the US navy out of the region.
‘They knew exactly what we’re going to do before we did it,’ a US general revealed
www.independent.co.uk
Biden is no fool by doing this as failing to make a clear signal that the US would react to an invasion of Taiwan makes such an eventuality significantly more likely.
Australia has discovered that the Chinese state will attempt to weaponise every tiny bit of economic leverage they have in order to make what they see as lesser states submit to them.
Also significant is that China considers the entire South China Sea and the coastal areas around them as their territory - they do not recognise them to be international waters in accordance with UN rulings.
What Australia has correctly inferred from this (and so has Japan) is that Chinese naval supremacy in the Pacific is extremely likely to lead to a scenario where naval blockades are routinely used to coerce countries in the region to submit to Chinese demands. A successful Chinese invasion of Taiwan, which would almost certainly also imply Chinese naval dominance in the region, could also make Japan, South Korea, Indonesia, Australia, Philippines, New Zealand defenseless against Chinese economic coercion, transforming them into tributary states.
It isn't just the US which has rabid nationalistic lunatics. The rabid nationalistic lunatics in China are basically the only voices permitted to speak in China now - more moderate voices are frequently deleted from social media or otherwise cajoled into silence if they deviate too much from the "patriotic" group think - and they are very serious about achieving the "Great Rejuvenation of the Chinese Race" of which annexation of Taiwan is an absolutely essential component.