Editor's note: Evan Thomas is editor at large of Newsweek and author of "The War Lovers: Roosevelt, Lodge, Hearst, and the Rush to Empire, 1898." His other books include "Sea of Thunder: Four Commanders and the Last Great Naval Campaign, 1941-1945" and "Robert Kennedy: His Life."
Washington (CNN) -- Recently, I was talking with an interviewer about men and war (I wrote a book about this), and she asked me, "What is it about testosterone that gets us into war?"
There is no doubt that women can fight. They do so every day in Afghanistan and Iraq. Though not permitted in the infantry in the U.S., they have seen plenty of action on a battlefield with no fronts. They are brave. They are also prudent.
Some men, maybe not so much.
In his correspondence between 1886 and 1898, for example, Theodore Roosevelt wrote enthusiastically about the prospect of war with Mexico, Canada, Britain, Germany and Spain. Roosevelt may have been an extreme example -- charging up Cuba's San Juan Hill, he exulted, "Holy Godfrey, what fun!" -- but he was hardly unusual in his eagerness for combat. When war against Spain was declared in April 1898, President William McKinley asked for 125,000 volunteers. He got over a million young American men almost overnight.
In those days, women were not permitted in the armed services. But what if they had been? Do women share the yearning for combat that has defined so many young men in so many societies, all through time?
I am tempted to say that women would be less likely to get us into wars. But then I remember Queen Elizabeth I (if you can't, just picture Cate Blanchett in body armor), British Prime Minister Margaret Thatcher (saying to President George H.W. Bush before the Persian Gulf War, "Now, George, don't go wobbly on me") and Golda Meir, prime minister of Israel during the Yom Kippur War (ordering revenge for the 1972 Olympics slaying of Israeli athletes). Does anyone doubt that gun-toting Sarah Palin would be ready to fight anyone, anytime? Hillary Clinton?
Still, I think women do not have the same primitive urge to test themselves in combat.
Back in Teddy Roosevelt's time, upper-class men in particular were determined to prove their manhood, fearful that they might be somehow exposed as weak and effeminate. This was particularly evident in Roosevelt's correspondence. He scoffs at his political foes as "hermaphrodites": roughly, half-woman, half-man.
Curiously, however, Roosevelt was introduced to the mythology and glories of war by a woman. Josephine Shaw Lowell was the widow and sister of two great Civil War heroes and martyrs, Charles Russell Lowell and Robert Gould Shaw. (You may remember Shaw's fatal charge with his doomed black regiment from the movie "Glory").
The young Josephine, a family friend of the Roosevelts', would visit wearing her widow's weeds and thrill little Theodore with the exploits of her martyred menfolk.
In her old age, Josephine Lowell turned against war. She had the wisdom to see that a war to free the slaves in America was noble but that foreign adventuring in Cuba and the Philippines had more to do with the atavistic urges of men than wise policy or moral duty.
Indeed, women may respond to the test of their essential identity in a less macho fashion then men. Although there were reportedly some problems with having women in the frontline units of the early Israeli army, women fought courageously and well in the Russian army against Germany in World War II. In the American military, women have taken on dangerous jobs. After some initial resistance, women fliers have been accepted by the brotherhood of naval aviators and air force pilots.
In the movie "Courage Under Fire," about a brave helicopter pilot in Desert Storm played by Meg Ryan, the men are shocked when Ryan cries. There is a wonderful scene in which Ryan tells the men to stop staring. "It's just tears. It doesn't mean anything," she snaps. Women are no less courageous than male soldiers, but they sometimes have less need to show off.
They certainly can bring a certain sense of humor that is useful in deflating male egos. After Teddy Roosevelt rode up San Juan Hill with his Rough Riders, his wife, Edith, went to Cuba to tour the battlefield. When she returned, she slyly told her husband that the hill of his famous charge was not quite as high as she had been led to believe. It is not known whether Roosevelt laughed.
The opinions expressed in this commentary are solely those of Evan Thomas.