For years, allegations of religious intolerance have swirled around the U.S. Air Force, with officers accused both of pushing evangelical Christianity on the troops—and of hampering Christians’ practice.

Now, a new case threatens to reignite the firestorm. The Air Force has allegedly refused to allow a service member to reenlist, because he refused to use the phrase “so help me God” in his oath, the American Humanist Association asserts.

According to the group, which has come to the defense of the unnamed airman—as Air Force troops are known—commanders told the service member on Aug. 25 that he must use the religious language in his reenlistment contract or leave the military.

The association wrote a letter dated Sept. 2, 2014, on behalf of the airman demanding that he be allowed to reenlist without invoking the religious language. Further, the letter threatens legal action against the airman’s commanders at Creech Air Force Base in the Nevada desert unless they reverse course. The complaint was previously reported by the Air Force Times.

“Because the law in this area is well established, those commanders may be sued in their individual capacities and be personally liable for damages,” Monica Miller, an attorney with the American Humanist Association’s Appignani Humanist Legal Center, wrote in the letter.

“The government cannot compel a nonbeliever to take an oath that affirms the existence of a supreme being,” Miller added.

Miller said during an interview with The Daily Beast that her client’s situation is not unprecedented. About a year ago, the Air Force denied reenlistment to a service member for similar reasons, Miller said, but quickly reversed course and allowed the airman to take a secular oath.

Until fairly recently, Miller said that the Air Force used to allow its troops to omit the “so help me God” phrase. But for reasons that are not entirely clear, the service changed its policy in recent months. “No one has been able to clearly articulate why they took that out,” Miller said.

Because there is plenty of legal precedent favoring her client, Miller said that she hopes the case can be settled without going to court. “We’d rather not take this to court,” she said. “We think it’s a pretty straightforward issue… Probably they were following policy, they just need to realize that the policy can’t be applied in an unconstitutional fashion.”

The Air Force did not respond to inquires about the incident. However, more than two dozen current and former servicemen spoke to The Daily Beast about the incident.

Most vigorously defended the air service. But one senior Air Force officer said that if the allegation about the airman in question is true, that it does not reflect well on the service. “I find it outrageous,” said the senior officer, who is a non-practicing, non-church-attending Christian. By and large there is no pressure to conform to a particular religion or even any religion in the service, he said. “I’ve been commissioned now since May ’92 and I’ve never seen any religious pressure. I was a cadet at the Air Force Academy before that for four years and didn’t feel the pressure either,” the officer said. “That said, I’m a Christian, so maybe they didn’t come find me and convert me, but I’m not in the pews on Sundays either. I’ve never seen any pressure on USAF [U.S. Air Force] personnel to be religious.”

While there may not be overt pressure to be religious—or particularly to follow branches of the Christian faith—that does not mean the Air Force can be less than sensitive to followers of other religions, a second former officer added. “In my 30 years in uniform and in my subsequent civilian life in the Air Force, I never saw a commissioned or enlisted member pressure a subordinate on the topic of religion. Never,” the former officer said in an email. “Of course, that does not mean the Air Force neglected to provide access to religious services to those who wished to worship while deployed, etc.”

Over the years, the Air Force in general and the Air Force Academy in particular have seen some of the most visible battles within the services over the issue of religious freedom. Indeed, in 2005, an investigation showed that the service had shown religious insensitivity but not necessarily discrimination toward other faiths. However, there is a thin distinction between the two. It was because of those very concerns that the service’s leadership under Air Force Chief of Staff Gen. Mark Welsh enacted a regulation that would prohibit commanders from promoting their religion to their charges—much to the ire of conservative politicians and lobby groups.

According to Jason Torpy, president of the Military Association of Atheists & Freethinkers (MAFF), the problem is the Air Force’s chaplains. “The Air Force, through its chaplaincy, provides a funded, well-resourced, and strongly empowered platform for god-beliefs that are primarily Christian in nature,” Torpy said. “However, these same services are denied to those who have positive beliefs and values that happen to be non-theistic.”

Torpy points out that in Air Force basic training, for example, the service does not allow for humanist alternatives to the Christian church. “There should be humanist alternatives to church in basic training,” he said. “We have some options in Air Force basic training and the Academy but that is due to commander approval, the courage of trainees themselves, and the effort of local volunteers. Chaplains have denied support to any of these activities. This may seem like equality, but when Christians get installation funds, integrated program advertisement, and the support of paid senior officers to coordinate activities while humanists must do everything by volunteers outside the normal system, then that is not equality.”

The MAAF, which was founded by former Air Force officer and attorney Mikey Weinstein, has had a number of run-ins with the service’s leadership over the issue of religious freedom since 2005. And while a small number of Air Force officers consulted by The Daily Beast conceded that there has always been a steak of religiosity within the Air Force, they pointed out that has always been the case with all four U.S. military services.

That being said, a number of officers—Christians, followers of other faiths, and atheists alike—said they had seen more anti-religious views being preached than religious ones. “I’ve actually found mostly to the contrary. I’ve experienced more ideological proselytization from anti-religious people than pro-religious people,” one officer said. “The idea that there’s some sort of structural compulsion to accept religion doesn’t jibe with my experience.”

Another senior wing-level officer agreed. “I never saw any pressure to force Christianity onto airmen. In fact I saw a lot more pressure to avoid sharing or showing religious beliefs of Christianity,” he said. “There is a pressure to find your spiritual pillar of personal fitness. We talk about four pillars of an airman in comprehensive airmen fitness. These are physical, emotional, mental, and spiritual pillars. So, yes, the Air Force is encouraging spiritual fitness but this is not to be confused with religion.”

By and large, the vast majority of the Air Force officers contacted by The Daily Beast did not consider the religious issue to be of particular import and said they did not feel pressure to conform to any particular faith. In fact, a number of officers were perplexed that religious freedom was considered to be a serious issue within the service. “My preference is a live-and-let-live culture, where faith or non-faith is part of your identity, and you respect the same in others by not using force or position or favoritism to advance your cause,” one Air Force officer said. “I think most Air Force people are this way.”

One senior field-grade Air Force officer pointed out that like any large organization, there are a large variety of people in the Air Force who come from all walks of life. “There are successful people and leaders who are religious, others who are atheist, and many in between,” the officer said. “I have not seen personally any instance where one's personal belief dictated imposition of a decision on grounds of that faith. I haven't found a correlation of success to faith to be compelling in my experience.”

As for this particular case where the Air Force is alleged to have denied an airman reenlistment because he refused to use religious terminology, most of the officers contacted by The Daily Beast suggested there were other factors involved. “I suspect there is far more to this story than ‘I didn't want to say God,’” said one retired official.