DALLAS (AP).- As commander of Allied forces in Europe during World War II, Gen. Dwight D. Eisenhower explicitly ordered his troops to safeguard objects of cultural and historical importance whenever possible — even while fighting a war of devastating destructiveness. Now, historians can hear the reasoning behind Eisenhower’s order, in his own words, thanks to the recent recovery of a recording of a speech he gave on April 2, 1946, at New York’s Metropolitan Museum of Art. Digging through museum archives, Robert Edsel, founder of an arts preservation organization based in Dallas, discovered the recording of Eisenhower’s speech that the general delivered when