A sacrifice is a voluntary, unasked for offering of something valuable to someone else, who can be a person or a nation and a sacrifice should have an immediate and beneficial effect on its receiver. It can involve a dangerous matter of life and death like a risk/reward calculation when donating an organ (eg Kerrie Packer). I wonder how many of the young men were aware that a bullet had their name on it. Of any nation. Anzac day, in my opinion, is for all the fallen in wars of all nations.
