Walzer discusses just and unjust wars, and the character of each. Think that's easy? It's not. War is politics and (as in the current Iraqi one) money. Walzer is a philosopher who thinks deeply about these violent episodes and the crimes that go with them. This is an important book.
When may violent means be used against another nation? This question is rarely asked before engaging in warfare, but seems essential: often nations engage for reasons that do not justify the deaths which will follow, and often do not engage when doing so might prevent great harm.
A basic premise in Just War philosophy is that the killing of civilians is always a criminal act. Military personnel must therefore be close to their targets before attacking them and be sufficiently trained to tell the difference between enemy soldiers and civilians. The premise that a nation may fight a war from long range with 'smart munitions' is therefore false. And the premise that an army's first duty is to protect it's troops from harm is also false; in order to kill enemy soldiers they have to accept casualties amongst their own.
This is a series of essays written between 1988 and 2003, so are influenced by events at the time of writing. The discussion of terrorism is particularly incisive and useful. A few, like those about the Palestinians' plight, seem absurdly hopeful, and all reflect Walzer's American background.
for anyone who thinks about politics, this is a must read.