What makes a war an illegal war?

But the concept of"legal" or"illegal" warfare depends usually upon how the war making apparatus of the a legally-installed government works. In the US, for example, one could say that anytime the US engages in military action not sanctioned by Congress that the country is making an illegal war since the Constitution spells out how war is to be declared. read more

Most other wars are illegal, such as Vietnam war and the all the Israeli wars on its neighbors from 1948 to 2009 (including the war on Gaza). I think an exception to this rule is starting a war to liberate lands of a certain country occupied by a foreign power, and that occupation is declared illegal by the UN. read more