Defending War

I write this with great caution, but it's something I've been thinking about.  I was sitting in a religion class the other day and the instructor brought up the subject of war and shared some quotes that were a little negative saying war was of the devil.  I was very uncomfortable sitting there.  Understand where I come from- I grew up as an Army brat until my junior year of high school, and now I'm an AF Wife.  My parents are very patriotic and always taught us what a great blessing we had of freedom.  My parents understood and shared with their children their love of country and that there were times where war was necessary- in defense of country, family, freedom, religion. 
I remembered a quote from a church leader shortly after the war on terror began.  He said,
"there are times and circumstances when nations are justified, in fact have an obligation, to fight for family, for liberty, and against tyranny, threat, and oppression.
"When all is said and done, we of this Church [the Church of Jesus Christ of Latter-day Saints] are people of peace.  We are followers of our Redeemer, the Lord Jesus Christ ... This places us in the position of those who long for peace, who teach peace, who work for peace, but who also are citizens of nations and are subject to the laws of our government.  Furthermore, we are a freedom-loving people, committed to the defense of liberty wherever it is in jeopardy...
"Now, there is much that we can and must do in these perilous times. We can give our opinions on the merits of the situation as we see it, but never let us become a party to words or works of evil concerning our brothers and sisters in various nations on one side or the other.  Political differences never justify hatred or ill will. "