China also has its own set of problems. Firstly, dependence on resources, including foodstuffs, which are mainly supplied by sea through a limited number of straits.
That is why China had worked hard on opening overland trade routes in it's BRI. It had been very successful in doing that. There is also Russia to north, who is one of the biggest exporter of foodstuff, minerals, and energy.
China have also secured food security for grains and crucial foodstuff. It's livestock industry still requires grain imports. But China can still import it's grains overland. Or just cut down on meat and dairy consumption.
Unlike China, SEA, Japan, and South Korea are almost exclusively dependent on sea trade. As such, they are the ones who will be in even bigger trouble if any straits are blockaded. And no, there is no such thing as 'selective blockade'. International shipping is too complex to enforce such a thing. Hence, everyone's shipping is gonna be blocked if a strait is blockaded. So anyone who is talking about blockading any straits to 'starve' China is not very intelligent.
Secondly, they are critically dependent on certain Western technologies;
Like what? Chips? China is only denied from the top-of-the-line Western chips. Which are only used in a limited amounts of top end electronics and computing. China is already at 7nm technology level, which is on par with contemporary technology. It is not as far-fetched as you might think for China to catch up with the West in a couple of years.
China had also exceeded the West in many other crucial technologies, like AI, 5G, and hypersonics. So stop living in bubble.
thirdly, they have enemies in their neighbourhood who themselves have significant military capabilities.
Like Japan and South Korea? So what? China have prepared to deal with them and the US combined. The Chinese would like to buy some more time to be in an even stronger position. But in an emergency, the Chinese are ready to deal with all of them today.
Fourth, their economy is indebted and unbalanced. If Xi is a madman like Putin, he can take the risk, but he most likely understands everything.
What are you smoking? That must be some really strong stuff.
All major economies are indebted. At least the Chinese know how to manage their debt. Their debt is nothing like the monster debts in Japan and the US.
What are you talking about 'imbalanced' economy? China has one of the most balanced economies on the planet. It is a real economy, with a massive industrial sector, and a service sector to serve it. The US, UK, and Australia have much more imbalanced economies. Their service sectors are much larger than their industrial sectors. The UK and Australia are even more grotesquely imbalanced.
China has a real economy. So it can actually survive an economic crisis. Because it can produce practically all the goods that everyone needs. The US instead, is best at producing financial junk like bonds, stocks, cryptos, and printed currency. Which are all gonna be reduced to worthless in an economic crisis.