I have read the book, seen the movie and seen the documentary on the History Channel (The True Story of Blackhawk Down I believe it was called). All were riveting in their own way, especially the book.
The most telling thing about this incident (in my opinion) was how clearly it illustrated the fact that we were in a "post-heroic" era of warfare. I define "post-heroic" as the notion that the only acceptable level of losses is zero.
We lost 19 men killed (almost everyone was wounded in some fashion). The Somalis lost somewhere between 1,000 and 10,000 people killed. That is somewhere between a 50 and 500 (!) to one kill ratio.
And still there was such a strong public reaction to losing any soldiers killed that the political pressure to withdraw was nearly insurmountable. We pulled out our troops and Somalia remains a hell-hole run by warlords to this day. Mission not accomplished.
I'll be the first one to say that we need to think twice before we go sending our men into every little brushfire war in the world. When that means sending highly trained FIGHTING men into a situation that requires "peacekeeping", we should be thinking three or four times.
But once the decision is made that the mission is worth engaging in, we should have the fortitude to stay the course even if it means the loss of some of our soldiers. If it is not worth losing those lives, I question whether it is worth putting them at risk in the first place.
As has been pointed out in this thread already, we seem to have adopted a new attitude when it comes to the "War on Terror". I have felt a sadness every time I hear of our soldiers losing their lives in Afghanistan. It is a terrible thing to have to give up your life in a foreign land away from friends and family. But it is even more terrible if that sacrifice is rendered worthless by a public and/or administration that will give up the fight as soon as a little resistance is encountered.
Ultimately, freedom is always paid for in blood. And it is always worth the price.