I have seen a few Indonesia/Australia wars timelines hereandthere, in some the US intervenes but takes its time or doesn´t intervene at all.
A war start between Australia and Indonesia. Washington is none too happy but Indonesia is an allie against communism too and have US equippement. UK is unhappy too but with the US not entering the war, Queen want Australia defended but the Prime Minister and/or parliament says no.
They put a weapon embargo on Indonesia and offer the sale of US equippement to Canberra, allow US volunteers and complaine about the whole thing to the UN. There is a lot of mediatic hot air and troop movements but not a single bullet fired.
This can happen either,
1) over East Timor in the late 1990s to early 2000s
2) 1981.
3) after a 2002 (or 2003) war against Iraq.
POD goes back preferably 20 years earlier in each case.
What would the international consequences be for each? For starter, the United States effectively breakes its part of the ANZUS treaty by not intervening, which would be seen even more negatively after Australia fulfilled its own part in Iraq.
In 1981 this could raise a few eyebrows too, especially in Germany, Taïwan or South Korea.