If China tries to "absorb" Taiwan the US will try to embargo shipping to China. Trying to embargo this in the South China sea could be too risky for the US because China has an established military presence there. The US may well step further out and blockade Chinese ships from going though the Makassar Straits and also past the Riau Islands.
These areas: a) Are in uncontested sovereign waters of Indonesia, Malaysia and the Philippines, b) Are closer to Australia, c) Will stretch the China navy supply lines, making it easier for a US alliance to attack the Chinese navy en-route.
The US is (as well as China) trying to win the hearts of the Indonesia Government which so far is keeping a strictly even policy of not picking sides between US and China. Perhaps Australia should adopt the same attitude.
