The following is a guest post by Kirstin J.H. Brathwaite, Postdoctoral Fellow at James Madison College, Michigan State University.

The graduation of two women from Army Ranger school last month along with the apparent intention of the Marine Corps to request an exemption to the Department of Defense’s plan to lift the combat exclusion policy has led to an outpouring of opinion pieces regarding the advisability of allowing women to participate in combat operations. Some argue that Capt. Greist and Lt. Haver’s success in one of the most demanding military training courses in the world proves that women are physically able to do the job. Others suggest that a few exceptions should not overthrow the rule. But a large number of those arguing against the inclusion of women in combat units accept that while some women may be physically capable of combat, their sex is a disruption to the most sacred of military institutions – the socially cohesive Band of Brothers.

According to this logic, the most important source of soldiers’ will to fight (or motivation, or general effectiveness in battle, depending on the author) is his relationship with the other men in his unit. As retired Marine Lt. Gen Newbold wrote HERE last week, “In this direct ground combat environment, you do not fight for an ideal, a just cause, America, or Mom and apple pie. You endure the inhumanity and sacrifices of direct ground combat because, ‘greater love hath no man than to lay down his life for his friends’.” Soldiers – especially ground combat troops – fight for their buddies. Women get in the way of the bonding between men. They disrupt the development of the Band of Brothers, which in turn reduces the combat effectiveness of the units in which they fight. If the band of brothers causes combat effectiveness, introducing sisters into the mix disrupts the band and reduces combat effectiveness.

The Band of Brothers argument thus makes three basic claims: (1) small unit cohesion leads to combat effectiveness; (2) small unit cohesion is a function of close emotional bonds between soldiers; (3) including women in combat units will disrupt the formation of close emotional bonds between soldiers. Megan Mackenzie outlines this argument, and major problems with each aspect of it, HERE and in her new book, Beyond the Band of Brothers.

To convincingly argue that the removal of the combat exclusion is a threat to U.S. combat effectiveness, one must first show that small unit cohesion does in fact lead to combat effectiveness. My own research calls this claim into question, and if the link between small unit cohesion and combat effectiveness is in doubt, and close personal bonds between soldiers have limited or even no impact on performance, whether or not women’s inclusion in combat operations disrupts these bonds is irrelevant from the standpoint of combat effectiveness. I therefore focus my attention on this first claim. I draw on recent literature regarding small unit cohesion as well as my own research on the causes of combat effectiveness to argue that small unit cohesion is not a major source of combat effectiveness. Rather, soldiers’ commitment to the cause (either due to a sense of nationalism, ideology, or other emotional commitment) is the most important source of combat effectiveness. Without commitment to the goal for which they are fighting, small unit cohesion can just as easily lead soldiers to avoid the fight as to fight hard in battle.

Logically, the idea that soldiers fight not for cause or country but for their buddies is flawed. The motivation to fight hard because you care for the men in your unit only leads to combat effectiveness if defeating the enemy is the only way to help your buddies. Generally there are other possibilities open to men who desire to keep themselves and the men around them alive. In my research I found that during the Second World War British Indian Army units – units made up of Indian soldiers specifically recruited and trained to have a strong sense of unit identity and cohesion – fled from battle in several instances. Entire units, not just individual soldiers, decided that leaving the battlefield was the best way to ensure they all survived. Men truly committed to the well being of their fellow soldiers might see the possibility of avoiding the fight as the best way of ensuring that well being. During the Vietnam War, some units went so far as to collectively decide to murder officers they believed to be incompetent, rather than risk death under their command (see THIS gated article by Elizabeth Kier). There is no necessary connection between close emotional bonds with fellow soldiers and effectiveness in combat.

Cohesion also has a dark side that its proponents rarely acknowledge. In his book, Ordinary Men, Christopher Browning points to the importance of men trying to maintain their social standing in the unit as a reason many individuals participated in the massacre of Jews during the holocaust. Robert Reilly argues that a similar force was at work during the Mai Lai massacre in Vietnam. There maintaining one’s position within the social group was so important that it led members of the unit to ignore or actively participate in the massacre of an entire civilian village (gated article HERE). I point out these human failings not to suggest that all strongly cohesive units will commit atrocities, but rather to suggest that cohesion in and of itself is not a virtue.

Empirically there is a great deal of evidence that small unit cohesion has little to no impact on combat effectiveness. In a Department of Defense commissioned study regarding the possible effects of allowing homosexuals to serve openly in the military (something that military leaders at the time claimed would disrupt cohesion), RAND found that there was no evidence linking close personal relationships between unit members to the unit’s performance of its duties (updated version of this study available HERE). In fact, strong social ties often reduced effectiveness as unit members put their relationships ahead of the goal. Instead, the study found that task cohesion – commitment of all members to achieving the group’s goal – had a measurable and positive impact on the unit’s effectiveness in achieving that goal. Commitment to achieving the goal (perhaps even commitment to the “cause”) is more important for combat effectiveness than social relationships between unit members.

In my own research on British Imperial Army combat effectiveness during World War II, I found that strong small unit cohesion only increased combat effectiveness where commitment to the cause was also present. Cohesive units who were not committed to the cause sometimes fled battle or demonstrated low morale, whereas cohesive units committed to the winning the fight showed great discipline and initiative in battle. Additionally, cohesion was actually not difficult to achieve. Units that suffered high losses in combat were often combined with other units they had never interacted with before, but the common experience of war quickly drew them together as comrades. Fighting together for a common cause was more important than social or even ethnic commonalities. Finally, small unit cohesion was not necessary to combat effectiveness – Australian soldiers consistently fought effectively throughout the war despite the fact that they had the least cohesive small units in the British Imperial forces. The influence of cohesion on effectiveness must be understood in relation to soldiers overall commitment to achieving their goal (task cohesion or perhaps even commitment to the cause). On its own, emotional bonds between soldiers can actually reduce combat effectiveness.

The Band of Brothers myth, as Megan Mackenzie has so aptly labeled it, has long dominated popular and military discourse about combat effectiveness. It is time to abandon that myth, and focus on building a truly effective military: one committed to achieving its goals by utilizing the abilities and talents of ALL those willing to serve