It's difficult for me to tell whether you wrote the above in sarcasm or in earnest.
To be sure, China has shown and will show some restraint when it comes to facing the provocations from the US and Taiwan, assuming the red lines are not crossed. As important as Taiwan issue is for China, it is playing a much bigger geo-strategic game with the US and, most of everything is going in China's favor, at a speed much faster than even the most optimistic had projected. We're not talking about some extremely long term prospect. Why upset the apple cart and disturb the trend?
China has the military capability to take over Taiwan today, with or without foreign intervention. Sure, it'll pay some cost; therefore postponing the final show down will put China in a better position to deal with any potential fallout. In other words, it's a matter of optimal timing. But the bottom line is, China has the capability to reunify Taiwan by force, and that gives her confidence to tolerate somewhat more insults. Because it knows that its adversary is desperate and is provoking for an error in judgement on China's part. China has shown herself to be a far superior strategic player than its adversary so far.
But that doesn't mean China's patience is unlimited. The provocations are cumulative and will eventually add up, should the adversary not stop, by which time China will be in a better position politically, diplomatically and morally to strike back. And it would strike back hard and overwhelmingly.
We've seen this pattern very consistently throughout the history of the People's Republic, from the Korea War when PRC was founded barely a year earlier, in the 1962 China-India War when India started to provoke on the border at least as early as 1959 and when China was pretty weak after the failure of the Great Leap Forward. We've also seen the same pattern in the most recent Hong Kong riot and its aftermath. In short, there are plenty of track records to back up China's consistent and tough responses to the challenges to its sovereignty and territory integrity, but not a single piece of evidence to suggest China will swallow the violation of its core interest. Not in the past. Not now.
And, just in case someone brings out the nuclear card. Here is the short answer: it won't work. China was the only country that had fought the two superpowers during the Cold War, against explicit or implicit nuclear blackmails. It invaded Vietnam in 1979 as punishment for Vietnam's aggression in Southeast Asia, knowing fully well that Vietnam had a mutual defense treaty with Soviet Union (the internal briefing from the top leadership had gone down all the way to the grass root level to prepare the populace for a possible conflict with the Soviet Union when the war broke out). People need to learn history before they threaten China's core interest. I'll leave it as that.
In addition to the above, I'm sure some people might ask "well if China thinks it can win a war with Taiwan +/-external intervention, why doesn't it just invade Taiwan now???" or "why don't the people itching for a war with Taiwan sign up to the PLA and volunteer to land on Taiwan's beaches"???"
I would advise those individuals to understand that China doesn't want war and military force to be the first option.
That is to say, when someone says "the PLA is willing to fight and and take Taiwan today if red lines are crossed" does not mean "China would like to fight and take Taiwan today in an unprovoked manner as its primary option of settling this issue".
The below factors should all be considered:
1. No one starts a war or fights a military conflict willy nilly, because war ultimately is not the most desirable way to achieve an outcome. After all, if you have to fight a war, it means you have failed in diplomacy.
2. China today, likely would prefer to settle the Taiwan issue without having to fire in anger -- i.e.: some sort of negotiated settlement obviously would be preferred, and the geopolitical realities of today and into the future means of course that any such negotiated settlement would be one where China has much more geopolitical cards to play than say a decade or two ago, so such negotiations would be on China's terms. It's understandable that Taiwan would not desire this for various reasons, but the desire for a negotiated settlement where the use of force is not needed is still preferable.
3. For China, the likelihood of a conflict over Taiwan being successful and the likelihood of a conflict over Taiwan being more "easy" for the PLA to achieve, only increases with time over the next decade or two, rather than decreases with time. That is to say, in terms of military capability (as well as geostrategic factors), time is on China's side with regards to the ability to defeat Taiwan and/or external intervention, and for at least the next two decades, China likely doesn't mind waiting because the balance of military power (both across the strait, in the region, and in the world) will continue to shift in its favour. All this is to say that if China was forced to fight a war over Taiwan but had the option to "choose"
when to fight a war over Taiwan, it would likely prefer to be able to do so more distant into the future rather than today. Every year that passes the balance shifts a bit more in its direction.
In short; the argument is that China is willing to fight a war over Taiwan today and is likely able to be successful in its political and geopolitical objectives, but that doesn't mean China is interested in fighting a war unprovoked today over Taiwan -- instead it reserves that capability in case any of its geopolitical red lines are crossed.
If those red lines are not crossed, then China will be content waiting for time to pass as they continue to build military and geostrategic power.
The only people who think China wants to fight a war over Taiwan today for no good reason either don't understand the whole point of "red lines" or who think China are somehow inherently aggressive for no logical reason and are irrational or something.
