According to the dominant position in the just war tradition from Augustine to Anscombe and beyond, there is no "moral equality of combatants." That is, on the traditional view the combatants participating in a justified war may kill their enemy combatants participating in an unjustified war - but not vice versa (barring certain qualifications). I shall argue here, however, that in the large number of wars (and in practically all modern wars) where the combatants on the justified side violate the rights of innocent people ("collateral damage"), these combatants are in fact liable to attack by the combatants on the unjustified side. I will support this view with a rights-based account of liability to attack and then defend it against a number of objections raised in particular by Jeff McMahan. The result is that the thesis of the moral equality of combatants holds good for a large range of armed conflicts while the opposing thesis is of very limited practical relevance.