Describing her role as a military chaplain, Rabbi Koppell states: "Chaplains are noncombatants—we do not carry weapons, we are not trained to fight. We are there to minister to the religious needs of the troops and, as such, we are an essential part of the military force. No one likes war, no one wants war. No one prays for peace with more fervor than the soldier who stands ready to lay down his or her life for our country.

Yet, I am not a pacifist; I believe that there are times when war is justified. War is always a horrible tragedy, but it is not necessarily immoral. I am proud to consider among my many identities as wife, as mother, as rabbi, as teacher, as friend, yet another—as an American soldier. G-d forbid the need should arise, our Jewish soldiers deserve to have rabbis who are trained and ready to deploy alongside them, to be there to offer all the support they will need. I am proud to be among those who stand ready to go with them."

Bonnie Koppell joined the Army Reserves in 1979 while a Rabbinical student at he Reconstructionist College in Philadelphia, Pennsylvania. Following basic training at Fort Dix, New Jersey, Bonnie headed to the U.S. Army Chaplain School at Fort Wadsworth/ Fort Hamilton, New York. Upon graduation, Rabbi Koppell became the first female Jewish chaplain ever to serve in the United States military.

When Operation Desert Storm broke out in 1991, Rabbi Koppell was immediately placed on active duty and ordered to report to the Academy of Health Sciences, a unit of the 5th Army Headquarters at Fort Sam Houston, near San Antonio, Texas. There, preparations were underway to med-evac an anticipated "massive" amount of American casualties resulting from a planned major ground offensive against Iraq. Bonnie was to provide for the spiritual needs of the sick and wounded, as the only Rabbi on staff. After being released from active duty, she was assigned to the 164th Corps Support Group in Mesa, Arizona.

Rabbi Bonnie Koppell was called to duty again in 2003, when she spent a month in Germany at the headquarters of the United States Army Europe. She then served a year of active duty in support of Operation Noble Eagle and was awarded the Global War on Terrorism medal in 2005. She celebrated Hanukah with Jewish service members in Kuwait and Afghanistan and was later deployed to Iraq, bringing Passover seders to soldiers in Baghdad and Taji in 2006.

Koppell, who holds the rank of colonel, has been appointed Command Chaplain of the 63rd Regional Support Command. She also serves as the rabbi to the Temple Chai community in Phoenix, AZ.