To my knowledge there is no law that prevents one nation state taking military action against another nation state.
I don't believe there is any requirement to have a United Nations ruling beforehand.
Each nation state has a sovereign parliament and government and is able to attack another whenever they want.
The international community may then show it's aquiesence or objection, and take action, accordingly.
This talk of Howard being a war criminal is pretty silly.
Constitutionally, in Australia the head of our armed forces is the Govenor-General.
Therefore if there is any case to answer internationally about this or any other matter involving our armed forces then it would be they who would be under the spotlight.
