"Poetry makes things happen." (W. H. Auden)
You know the old saying "Life imitates art." Such is the case with poetry. The power of the pen is mighty. An aptly written poem can change the world as we see it. Here are some anti-war poems which moved their readers.
On Christmas Day in 1864, Henry Wadsworth Longfellow, wracked with grief after the tragic death of his wife and the crippling of his son in the Civil War, penned Christmas Bells. Set to music in 1872, it became the Christmas carol "I Heard the Bells on Christmas Day" (http://en.wikipedia.org/wiki/I_Heard_the_Bells_on_Christmas_Day).
After seeing his fellow soldier gunned down on a World War I battlefield in France, Dr. John McCrae wrote the rondeau In Flanders Fields, now recited in schools across Canada on Remembrance Day (http://en.wikipedia.org/wiki/In_Flanders_Fields).
Soldier Frank Gibbons wrote A Beach in France, dedicated to the memory of British Sergeant Arthur Walton (http://www.goodreads.com/topic/show/954374-world-war-two-poetry).
After four anti-Vietnam War protesters were gunned down by the National Guard at Kent State University in 1970, Crosby, Stills, Nash and Young composed the song Four Dead in Ohio (https://www.youtube.com/watch?v=68g76j9VBvM).
Michael Burch wrote the villanelle Because Her Heart is Tender, on the first anniversary of 9/11:
She scrawled soft words in soap: "Never forget"
dove-white on her car's window (though the wren,
because his heart is tender, might regret
it called the sun to wake her).
As I slept,
she heard lost names recounted one by one.
She wrote in sidewalk chalk "Never forget"
and kept her heart's own counsel, no rain swept
away those words, no tears leave them undone.
Because her heart is tender with regret
bruised by razed towers' glass and steel the stone
that shatter on and on and on and on...
she stitches in damp linen: "NEVER FORGET"
and listens to her heart's emphatic song.
(The wren might tilt his head and sing along
because its heart once understood regret
when nestlings fell beyond, beyond, beyond...
love's reach, and still the boot heeled toe strode on.)
She write in adamant: "NEVER FORGET!"
because her heart is tender with regret.