Washington — America’s military service chiefs, in separate letters to a senior senator made public Tuesday, expressed resistance to legislation that would alter how commanders decide which allegations of major crimes to prosecute, putting themselves directly in the middle of a political fight that transcends party lines.

The mid-May letters to James M. Inhofe of Oklahoma, the top Republican on the Senate Armed Services Committee, indirectly but unmistakably criticized a bill by Sen. Kirsten Gillibrand, D-N.Y., that has attracted an almost unheard-of 66 co-sponsors.

Her bill, and a similar one to be introduced in the House last Wednesday, would require that decisions on prosecuting most major crimes in the military — including sexual assault but also including murder and more — must be made not by commanders but by trained military prosecutors. The change would not affect treatment of military-unique crimes such as disobeying an order.

Most significantly, the military service leaders all argued in their letters that whatever legislation Congress passes this year on the subject should only remove from commanders’ hands the prosecution decisions they must make on sexual offenses, not a wider gamut of felonies.

In stating this view clearly and in writing now, the service chiefs have aligned themselves with a position held by certain senators — and perhaps vice versa. The senators who want to limit the scope of any coming change include Inhofe and Rhode Island Democrat Jack Reed, the Senate Armed Services Committee chairman.

Some of the chiefs also said the Gillibrand bill could hurt military readiness by creating new costs and delays — arguments that are very much in dispute.

Inhofe, in a statement Tuesday, effectively said that the chiefs believe Gillibrand’s bill could hurt the military’s ability to perform its missions and that any legislation should be “limited in scope to sexual assault and related offenses.”

Gillibrand fired back in a statement of her own on Tuesday.

“From racially integrating the armed forces to enabling women to serve in combat to allowing LGBTQ service members to serve openly, the chain of command has always fought to protect the status quo, just as they are doing here,” Gillibrand said. “Their arguments are recycled talking points from the battles for progress in the past and are void of any coherent argument beyond the disingenuous ‘good order and discipline.’”

Which crimes?

The letters to Inhofe were written at his request by Army Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, as well as the top officers in the Army, Air Force, Navy, Marine Corps, Space Force and National Guard Bureau.

Milley had previously hinted that he was open to supporting a change in how prosecution decisions are handled if it were limited to covering sexual offenses.

But the newly revealed letters put Milley and the other chiefs clearly and explicitly on the record about Gillibrand’s bill and a comparable measure by Reps. Jackie Speier, D-Calif, and Michael R. Turner, R-Ohio, among others.

Speier had previously written bills that would make the change just for sexual crimes, but her new bill is broader, like Gillibrand’s.

The letters from the brass make plain that the members of Joint Chiefs of Staff — who, as an institution, have fiercely resisted any changes at all to military prosecution decisions ever since Gillibrand and Speier first started pushing for them about eight years ago — now support them, but only for sexual crimes.

It became apparent earlier this year that Congress was going to make changes after the military had failed for years to solve the problem of sexual assault in the ranks. As a result, the chiefs’ newfound acceptance of the change is arguably a recognition of a fait accompli and an attempt to limit its effect.

The military leaders’ letters also underscore the fact that the question now on this issue is no longer so much whether Congress will change the law as it is merely, which crimes will be affected?

The Gillibrand-Speier approach, covering all major nonmilitary crimes, is backed by a supermajority sufficient to overcome a filibuster. It is also backed by a majority of the Senate Armed Services Committee, which will consider in a few weeks how to address this issue in the defense authorization bill, known as the NDAA.

There is no sign that the chiefs’ missives will affect those whip counts.

However, Gillibrand has been open about her fear that, even if she wins the battle in the House and Senate, Armed Services conferees could still dilute her provision beyond recognition behind the closed doors of an NDAA conference committee.

Reed and Inhofe, unlike most of their colleagues, are not only backing the more limited approach, they have also blocked Gillibrand’s repeated attempts in recent weeks to get unanimous consent for a Senate floor vote on her bill.

Chiefs’ ‘concerns’

The chiefs, in their letters, were united in wanting to limit any changes to cover just sexual crimes, though some expressed their views as “concerns,” while others said more definitively that any new law should be limited.

Some of the chiefs offered additional arguments against the Gillibrand-Speier proposal, though none referenced it or the lawmakers directly.

For example, Gen. James McConville, the Army chief, argued for a three-year trial period to assess any changes.

Gen. David Berger, the Marine Corps commandant, called the Gillibrand-Speier proposal “a significant risk to readiness and mission accomplishment.” He also said the bill’s 180-day implementation period is too short.

Berger also expressed worries about delays in prosecutions and added costs.

‘Pink court?’

To Gillibrand and her allies, limiting the bill to sexual crimes is senseless. There is the risk, they say, that in creating a special process for sexual crimes — a so-called “pink court” — this would reinforce the myth that allegations of sexual offenses are treated specially and not typically in a way that is fair to the accused.

It is also not clear how two separate systems for deciding on prosecutions would handle allegations against someone that mix both sexual and nonsexual offenses, some observers have pointed out.

Don Christensen, a former Air Force colonel who was a top prosecutor for the service, said in an interview that the chiefs’ concerns about “good order and discipline” and “readiness” are unfounded.

“For some reason, the chiefs now say: ‘It won’t affect good order and discipline if we take decisions on prosecuting sex crimes away from top commanders, but it will have an effect if we take murders away.’ That doesn’t make sense,” said Christensen, now president of a human rights group called Protect Our Defenders.

Addressing the contention by some of the chiefs that the Gillibrand-Speier proposal would require more bureaucracy and money, he predicted the opposite would come to pass.

Under the military’s status quo, he said, about 99 percent of the roughly 14,500 commanders do not make decisions on whether to prosecute allegations of felony-level crimes within their units. The commanders instead refer allegations about such crimes to the 1% of senior officers who are empowered to make such decisions.

As a result, he said, the current system usually requires criminal prosecution recommendations to go through multiple layers of command, and legal advice is typically needed for commanders to make decisions, because generals and admirals rarely have legal training.

“That’s another scare tactic,” he said of the bureaucracy argument against the Gillibrand-Speier bill.