China has tended to be non expansive militarily but still take actions to secure and defend China.
The recent concentration on building up the military has very little to do with defending China, which in any case has not been threatened militarily by any other nation.
China has been building trade alliances.
Correct. Some call it "soft power". Not always a bad thing.
China has been accused of being infiltrative in other nations. China has I think mentioned it being time for Taiwan to come home.
China has taken a threatening stance towards Tiawan. Many signs are there, in terms of China's military buildup, that it is planning for a possible military invasion of Tiawan.
The Tiawanese people, for the most part, consider themselves to be an independent nation, and they want things to stay that way. The Chinese authoritarian regime has other ideas.
My question is this- Is China's intention still non expansive and aimed at self sustaining in the face of threats etc from the US?
In the short term, I think it is most likely that China's expansionist intentions are concentrated locally. Taiwan would be its first target. After that, who knows?
With the United States taking its eye off the ball, it might come down to a question of what China thinks it can get away with. Compare, for instance, the ongoing situation with Russia and the Ukraine. The US has mostly taken its eyes off that ball and the Ukrainian people are experiencing the bulk of the suffering as a result, although the EU and other nations have stepped in to some extent to fill the vacuum left by the Americans. The Russian people haven't gone unscathed, either. It is mostly the poor Russian conscripts who have borne the brunt of Putin's war of aggression, on the Russian side, but the Russian regime has never cared very much about the general Russian populace. It is a typical authoritarian kleptocracy.
Does China want to lead the world or secure China?
Chine is already leading the world, in many respects. Technologically, it is gaining on the US and is level or surpassing it in some areas. In terms of trade, China is an economic powerhouse. In terms of taking serious steps to address climate change, it is way ahead of the US, whose government has, for the time being, kept itself in the dark ages with its promotion of fossil fuels. The US's own goal that has resulted from Trump's tariffs has helped to ensure that China's economy will overtake the US's.