Wars never fit neatly into clean templates. But we can divide them into certain categories: wars of conquest, civil wars, rebel wars, insurgency wars, religious wars. Recent history has also seen proxy wars, preventive wars, regime change wars, and the post-9/11 global war on terrorism, centered on Afghanistan and Iraq. The political philosopher Michael Walzer went one step further when he tried to determine the moral arguments behind war, dividing them into “just” and “unjust” wars—that is, wars that should be fought on humanitarian grounds and those that are not.
