Infantry: Diligence Not Flirting Will Keep You Alive, by Jim Dunnigan.

Modern infantry combat is intensely physical, and most women remain at a disadvantage here. There are some exceptions for specialist tasks that do not involve sturdiness or strength, like sniping.

Then there is the hormonal angle. Men generate a lot more testosterone, a hormone that makes men more decisive and faster to act in combat. It was long believed that testosterone makes you more aggressive. When examined carefully it was found that the effect was to make you more aware and decisive. That can be seen as “aggressive” but it is being more aware and decisive that makes a difference in combat. Aggressiveness alone will just get you killed sooner. …

Going into the 21st century, warfare is becoming more automated and less dependent on muscle and testosterone. That gives women an edge, and they exploit it, just as they have done in so many other fields. What women continue to avoid is traditional infantry jobs, which are less needed but not going away. …

In the last century, there have been several attempts to use women in ground combat units, and all have failed. When given a choice, far fewer women will choose combat jobs (infantry, armor, artillery). But duty as MPs does attract a lot of women, as do jobs like fighter, bomber, helicopter pilots and crews, and aboard warships. …

Male and female Israeli officers both report that it is not a good idea to put men and women together in observation posts or other isolated situations that require sustained concentration and alertness. … Men and women serve together on patrols and observations posts with the understanding that diligence and not flirting will keep you alive.