Why I like Enterprise's much-maligned Xindi story

The Xindi story line of Enterprise is a surprisingly nuanced response to 9/11 and subsequent events, tackling such questions as, is it okay to respond out of vengeance, or only self defense? Are there some moral absolutes that can’t be broken, even to save millions of lives? In war, how do we weigh the lives of the enemy against our own? How good does intelligence have to be to justify killing, or even starting a war? Is killing to prevent possible, even probable future killing defensible? Who decides, the military, the politicians, the citizens? How do people who have seen and done terrible things in the line of duty move on with their lives? And it’s not preachy or facile – it really digs into the grey areas.