I have seen war. I have seen war on land and sea. I have seen blood running from the wounded. I have seen men coughing out their gassed lungs. I have seen the dead in the mud. I have seen cities destroyed. I have seen two hundred limping, exhausted men come out of line — the survivors of a regiment of one thousand that went forward forty-eight hours before. I have seen children starving. I have seen the agony of mothers and wives. I hate war.

Franklin Delano Roosevelt (1882–1945) American lawyer, politician, statesman, US President (1933–1945)

Speech (1936-08-14), Chautauqua, New York
    (Source)

(Source (Video); dialog confirmed).

FDR, as Assistant Secretary of the Navy, visited the front lines of WWI in France after American troops were in service.