Most guys know that you’re supposed to hold a door for a woman.

Most guys also know that when you do hold the door, some liberal women give you “the look.”

“The look” is that furrowing of the brow, that particular annoyed set of the mouth that ladies get when they’re thinking about causing bodily harm to a man.

“The look” makes men want to cross their knees in self-defense.

Rick Santorum got “the look” from liberal women last week when he expressed skepticism about a Pentagon plan to put more women closer to the front lines in combat situations.

Santorum, who seems to be a chivalrous kind of guy, tried to explain that male soldiers, who are also often chivalrous kind of guys, might be tempted to protect any women in their unit to the possible detriment of their mission.

To men who like women, this statement made perfect sense. To women who like men, that’s exactly the sort of behavior to be encouraged, albeit probably not in combat situations when most women would prefer their men concentrate on dodging bullets.

“I do have concerns about women in front-line combat,” Santorum said. “I think that could be a very compromising situation, where people naturally may do things that may not be in the interest of the mission, because of other types of emotions that are involved.”

Unfortunately, Santorum made the mistake of using the word “emotions” during all of this, and the ears of liberal women instantly perked up because they thought Santorum was saying that women are too emotional for combat.

Then they proceeded to get all emotional on Santorum, calling him all manner of names and whining that Santorum thinks women can’t hack combat.

Which is funny because many liberals typically go into the military to get Uncle Sam to pay their college tuition. The last place most of them want to be is near the front lines of combat.

Still, Santorum needn’t worry so much about American women going into combat.

American women are tough.

Santorum might consider the story of “Molly Pitcher,” who according to legend jumped in to take her husband’s place behind a cannon when he fell in combat at Monmouth, New Jersey, during the Revolutionary War. Her actions allegedly inspired her husband’s unit to fight back the British troops and earned her the respect of some general named George Washington.

Then there’s the case of Deborah Samson, another Revolution-era lady, who cut her hair, bound her bosom and joined the Continental Army using her brother’s name. She was wounded in combat, but the doctor who treated her so admired her actions that he kept her secret and allowed her to recuperate at his own estate. She retired at the end of the war with an honorable discharge and a pension.

My own mother, for another instance, was a nurse and once knocked out a bad guy by hitting him in the head with her shoe.

See? Tough.

As long as the standards aren’t dumbed down for women, I say give ‘er a big honkin’ cannon and may God have mercy on our enemies’ souls.

Tad Cronn is the editor in chief of The Patriots Almanac, a nonprofit educational quarterly magazine.