What it takes to defeat evil.

I've been reading in the Bonhoeffer biography about some of the various attempts to kill Hitler throughout the war (there were far more attempts than most people realize beyond the famous Valkyrie plot).  Each attempt ended in failure, for a variety of often mundane reasons.  Bonhoeffer's advice to a Christian German staff lieutenant, Werner Von Haeften, (one of Stauffenberg's aides) who in his duties was close enough at times to Hitler to take out his revolver and shoot him, offers insight.  He cautioned this brave man that to simply kill Hitler was not enough.  Evil could not be so easily defeated; there were many of Hitler's henchmen (Himmler, Goring, Goebbels) who were as vile as he was and who would take up his cause if he were removed.  I think that we've identified Hitler so closely, and for good reason, with the Holocaust, that we've forgotten how very many individuals were a part of the evil he unleashed.  It was not hundreds, or even thousands, but tens of thousands of "ordinary" soldiers, functionaries, and citizens who actions helped the Nazis murder millions.  Beyond them, there were countless others who stood idly by, who failed to act, and whose inaction made them complicit in the crimes against the innocent.
What do we learn from such things?  That evil is not easily defeated.  It can be destroyed, but not in one fell swoop.  We would rather believe that easy solutions exist, that wars can be waged cleanly, that one politician is responsible for our troubles, etc. than come to grips with the reality that evil (on a grand scale) could never exist without many helpers.
We should also remember that the efforts of those who fail to defeat evil, even if they're martyred in the process, are never wasted.  Such honorable sacrifice will always ripple throughout our world and down through time as it inspires others to take action even when the prospects for victory seem slim.
In the end, our responsibility is to God.  We must answer when our time here is over for our efforts and contributions.  Did we stand by and let others suffer?  Did we take action for the sake of Christ?  Among the list of victims of the Nazis are a number of good Christian men and women who were martyred for their faith; they met God with a clean conscience.