From Lynn Sislo:

... from The Fellowship of the Ring:
"I wish it need not have happened in my lifetime," said Frodo.
"So do I," said Gandalf, "and so do all who live to see such times. But that is not for them to decide.
All we have to decide is what to do with the time that is given us."

From Glenn Reynolds at Instapundit:

... from Eowyn: "It takes but one to make a war, not two, and those who do not take up swords can still die upon them."

where he also says that

Michael Drout sends this:

This one, from The Return of the King, is what I sent to several of my
students last year who wanted to turn to literature:

"Other evils there are that may come; for Sauron is himself but a servant or emissary. Yet it is not our part to master all the tides of the world, but to do what is in us for the succour of those years wherein we are set, uprooting the evil in the fields that we know, so that those who live after may have clean earth to till. What weather they shall have is not ours to rule."

A fairly good answer to those who suggest that we have to solve every other problem (i.e, Israel / Palestinians, poverty in the third world, racism, etc.) before we can tackle terrorists.

From Bigwig at Silflay Hraka: 

...for those who take up arms in this age against the West.

"All were slain save those who fled to die, or to drown in the red foam of the River. Few ever came eastward to Morgul or to Mordor; and to the land of the Haradrim came only a tale from far off: a rumour of the wrath and terror of Gondor."