As published in the New York Times “Room for Debate” on women serving in combat roles.

As a female Marine combat veteran of the Iraq war, or just as someone with common sense, I urge Secretary of Defense Ashton Carter to maintain the combat exclusion. We need our combat units to be the most lethal fighting force our tax dollars can buy. Adding women creates more danger for everyone and risks compromising missions.

Men make the infantry standards all the time. Women fail to make them a lot of the time.

Even on lower fitness standards, women have far higher rates of injury, illness, non-availability, non-deployability and attrition than men. Commanders of coed units know too well the added burdens of trying to juggle sexual dynamics, accommodations, relationships, fraternization, rape, pregnancy, hygiene and much more while maintaining troop welfare and good order and discipline, let alone mission accomplishment. These are liabilities that can result in mission failure and high casualties in the combat units, all to satisfy a tiny group of women selfishly petitioning for their own career advancement.

ISIS doesn’t care that our military has met its diversity quota and broken the so-called brass ceiling. They will see our self-imposed weaknesses and exploit them to cause as much damage as possible. That’s precisely what happened to the group of female Marines who served on entry checkpoint duty two months before I did in Fallujah in June, 2005. Insurgents targeted their convoy almost certainly because they were transporting females. They laid an ambush that began with a bomb and ended in a firefight. Three American servicewomen died (one was a single mother) and several others suffered horrendous injuries. They hadn’t made and maintained the infantry standards to be there — they were just attached to the infantry by day. Women are targeted as easy marks because their capture and torture devastate American morale, further hindering our ability to fight our enemies.

Women can serve their country in all sorts of noble capacities and enjoy long and lofty military careers. Maintaining the combat exclusion doesn’t take anything away from them. It elevates and protects women and empowers the combat units to succeed in fighting America’s vicious enemies.