How should America respond to Syria’s use of chemical weapons?

WASHINGTON — On April 22, 1915, chlorine gas, wafted by favorable breezes, drifted from German lines toward enemy positions held by French troops near Ypres, Belgium. This was the first significant use of chemical weapons in a war in which 100,000 tons of chemical agents would be used by both sides to kill almost 30,000 soldiers and injure 500,000. The injured would include a German corporal whose voice, bearing traces of a gas attack, carried him, 15 years later, to Germany’s pinnacle. The man who was U.S. president when Adolf Hitler committed suicide 30 Aprils after Germany’s 1915 gas attack had been Capt. Harry Truman in 1918 when his artillery unit fired shells containing some of the chemical agents that the Allies had developed in response to what Germany did in 1915.