The writer, a retired Army major general, is a former commandant of the Army War College.

Recently The Post reported that four women serving in the Army, two with Purple Hearts, had filed a federal lawsuit seeking to overturn the military’s combat exclusion policy. “Combat exclusion” is code for being kept from serving in the close-combat arms of the Army, Marines and special forces. These units are made up of soldiers whose purpose is to kill the enemy directly. They also do virtually all of the military’s dying: Since the end of World War II, four out of five combat deaths suffered by men and women serving in the U.S. military have been in the infantry, which includes more than 6 percent of the active-duty military.

I’m torn by this issue. My family has served in the military for three generations. My father fought in World War II and retired a colonel. Both of my kids served as officers. Both commanded their ROTC battalions, at Wake Forest and Notre Dame, respectively. Both were paratroopers. Both served in combat divisions, one in Bosnia and Kosovo. And both are women.

So I have some emotional skin in this game. First, I’m disturbed that these four soldiers are using the courts to decide the issue. The courts know the law of the land, but they know nothing about close combat and the intimacies of fighting and dying within a small unit. Second, while the ground services have done a spectacular job of integrating minorities including African Americans, Hispanics and now gays, they still have a long way to go to achieve perceptual equality for the female rank and file. One need only read the statistics about personal assaults among serving women to make the case.

Today women are excluded from three branches of the ground services: artillery, armor and infantry. I have no problem with integrating women into the artillery. I commanded an artillery brigade in the 1980s where women served as gunners. Fifteen of my battery commanders were women, and they performed spectacularly. I still hear from some of them who retired recently as colonels. Artillery is okay for women because the purpose of the guns in battle is to deliver firepower against a distant enemy, not to engage in close combat. Some do, to be sure. I received the Silver Star for defending my artillery firebase in Vietnam. But artillery close combat is incidental.

Infantry and armor soldiers alone do virtually all the intimate killing. Here’s where the issue gets hard for me. Intimate killing is done in small units, normally squads and teams. In these engagements they fight and often die not for country or mission but for each other. We borrow a phrase from Shakespeare’s “Henry V” and term this phenomenon the “band of brothers effect.” This is the essential glue in military culture that causes a young man to sacrifice his life willingly so that his buddies might survive. Contemporary history suggests that U.S. infantry units fight equally well when made up of soldiers of different ethnicities, cultures, intelligence and social background. The evidence is also solid that gays make just as good infantrymen as do straight men.

I’ve been studying the band of brothers effect for almost 40 years and have written extensively on the subject. We know that time together allows effective pairings — or “battle buddies,” to use the common Army term. We know that four solid buddy pairings led by a sergeant compose a nine-man, battle-ready squad. The Marine squad is slightly larger. We know from watching Ranger and special forces training that buddy groups form often spontaneously. But the human formula that ensures successful buddy pairings is still a mystery, and that’s the key stumbling block in the debate. Veteran SEALs, special forces, Rangers, tankers and line infantrymen will swear that the deliberate, premeditated and brutal act of intimate killing is a male-only occupation. But no one can prove it with data from empirical tests because no such data exist from the United States. They just know intuitively from battlefield experience that it’s true.

To be sure, women soldiers may be fit, they may be skilled and they may be able to “hang.” Many have proved with their lives that they are willing to make the ultimate sacrifice. But our senior ground-force leaders, as well as generations of former close combat veterans from all of our previous wars, are virtually united on one point: The precious and indefinable band of brothers effect so essential to winning in close combat would be irreparably compromised within mixed-gender infantry squads.

The military has only about 7,000 squads. This thin red line is already fragile from overuse in Iraq and Afghanistan. For the moment I have to side with my infantry comrades in arms. Let’s get the data, study the band of brothers effect to make absolutely sure women will fit in before we take the plunge — and for heaven’s sake keep the decision away from lawyers and judges. Of course, one of my combat daughters is now a lawyer. But both of them reluctantly agree with my caution.

Read more from Opinions:

Five myths about women in combat

Jena McGregor: Military women in combat — Why making it official matters

Robert McCartney: Women have equal opportunity to serve in military — and to sacrifice their lives