Beijing is planning world’s longest rail tunnel to link Taiwan to mainland

"What will China actually gain from this? Not much besides scoring some political gains at home which they don't need anyway."

China views Taiwan as inexorably part of their homeland. The existence of a 'separate Taiwan' is kind of like a permanent stain to them.

Imagine if during major American political upheaval, Texas became it's own state again, and after takeover by Central/South American political entities, decided not to rejoin the rest of the US as the political situation stabilized.

Americans wouldn't rest until they reclaimed it.

I'm not justifying it and personally I would have liked to have seen a 'Chinese Federation' i.e. Hong Kong, Taiwan, mainland China, possibly even Manchuria as separate entities, possibly with 'Tibet' as managed-but-autonomous region. Instead of a single autocracy.

Aren't there massive gas fields suspected in the ocean around there? Extending the territory and claiming the fields could be a motive.

From a military perspective, Taiwan is a extremely important to China because of where it is located. Their fear is that the US would use Taiwan as a base of operation to refuel and attack China. It’s in their best interest to reclaim that land.

Like all politicians, domestic policies are usually harder to gain political points vs foreign policies. It is also much harder to fix when problems arise. This is why head of states like the US president have traditionally spent more time on foreign policy. All leaders think about their legacy. If Xi can reclaim Taiwan, he will be remembered for decades. That is powerful motivation for any leader, especially one that is elderly.

The US is currently run by a lunatic. Are you so sure Trump would impose sanctions? Most of his decisions are made in a fit of rage, rather than thoughtful thinking. The fact he met with Kim, should tell you something about his decision making. The problem is Americans has played this big brother role for the last 50 years, but now there is a potential contender on the playground. I am not sure the US can do much here considering China is cash rich to withstand any sanctions you impose on them. China can use Trumps playbook too if they wanted like subsidising farmers, but they haven’t cause they don’t need to.

> EU will likely join in.

Doubtful. The EU, and France in particular, has been selling China weapons for over a decade.

Isn't that until the Chinese play catch up and copy all the technological competitive advantage the West currently enjoys?

Even more interesting for China then, Crimea had just a warm-water port

On the other hand much of the world is more dependent on China's cheap manufacturing and products than anyone was for Russian products which makes sanctioning (or going to war with) them much harder. It'd definitely be interesting to see how far the One China but not really policy that most of the world follows will stretch if/when China actually makes an Over move against Taiwan.

"The United States will immediately initiate a hot war against China and attempt to decapitate China's government if China attempts to annex Taiwan. "

Oh gosh, not quite.

This is a kind of cold war policy with caveats.

If China escalates militarily, US will likely tit-for tat and yes, may be involved in actual, armed conflict as it escalates Ex: China sends Aircraft carrier, US does as well, small gunboat firefights ensue, US participates, maybe some naval firing back and forth, Chinese marines found on Taiwan, US marines land as well, China does electronic attacks, US response.

But ...

In an unlikely 'Blitzkrieg' scenario, whereby China launches a very swift and unanticipated attack on Taiwan - say: multi-beachead marine landing, paratroopers, 5th column destruction of comms equipment, drone and cruise missile attacks, total electronic-warfare shutdown - and the Chinese have militarily occupied most of the major and important installations in say, 48 hours ...

Do you think the US is going to ramp up 500K soldiers and 'invade Taiwan'? It would be logistically difficult, and militarily questionable: the Chinese are well armed, and can fight, and landing beachheads in that scenario, so far from home, against a large enemy may simply be futile. In fact, the Chinese may possibly be able to easily defend themselves against very vulnerable US Navy ships these days.

The US/world reaction may be to use the US Navy to blockade Taiwan and all of China, and to launch electronic and economic attack on China.

But I doubt if the US would respond in a full-on WW3 scenario.

As the commenter posted, a gradual, even softer-than-Crimea takeover is much more likely.

Supporting pro-China elements in Taiwan, spending a generation 'educating' (i.e. propaganda) Taiwanese that they are in fact part of 'mainland China', using coercive economic incentives ... I think that Taiwan may ultimately join China through a slightly shady but nevertheless 'legal' popular referendum.

The Chinese have the advantage of taking a very 'long view' of things and can have '50 year plans' for such things. Western democracy unfortunately doesn't allow for that so often.

> slightly larger than that of Australia.

This is false. It's slightly smaller.