Reforms mark the most sweeping change to the US military legal code since its creation in 1950, the White House says.

The order on Friday formally implements legislation passed by Congress in 2022 aimed at strengthening protections for servicemembers, who were often at the mercy of their commanders to decide whether to take their assault claims seriously.

“These reforms are a turning point for survivors of gender-based violence in the military,” the White House said in a factsheet outlining the changes.

“They fulfill President Biden’s promise to fundamentally shift how the military justice system responds to sexual assault and related crimes, which is something President Biden has prioritized since Day One of this administration.”

Members of Congress, frustrated with the growing number of sexual assaults in the military, fought with defence leaders for several years over the issue.

They argued that commanders at times were willing to ignore charges or incidents in their units to protect those accused of offences and that using independent lawyers would beef up prosecutions. Military leaders baulked, saying it could erode commanders’ authority.

The change was among more than two dozen recommendations made in 2021 by an independent review commission on sexual assault in the military that was set up by Defense Secretary Lloyd Austin. And it was included in the annual defence bill last year.

But since it requires a change to the Uniform Code of Military Justice (UCMJ), it needed formal presidential action.

The measures “represent the most significant transformation of the military justice system since the UCMJ was established in 1950”, the White House said.

“The historic reforms announced today will better protect victims and ensure prosecutorial decisions are fully independent from the chain of the command.”

Thousands of reports

The Pentagon had already been moving forward with the change.

A year ago, the Army, Navy, Marine Corps and Air Force set up the new special trial counsel offices, which will assume authority over prosecution decisions by the end of this year. Beginning January 1, 2025, that prosecution authority will expand to include sexual harassment cases.

The changes come as the military continues to grapple with rising numbers of reported sexual assaults in its ranks.

While the services have made inroads in making it easier and safer for troops to come forward, they have had far less success reducing the number of assaults, which have increased nearly every year since 2006.

Overall, there were more than 8,942 reports of sexual assaults involving service members during the 2022 fiscal year, a slight increase from 8,866 the year before.

Defence officials have long argued that an increase in reported assaults is a positive trend because so many people have been reluctant to report them, both in the military and in society as a whole.

Greater reporting, they said, showed there is more confidence in the reporting system, greater comfort with the support for victims, and a growing number of offenders who are being held accountable.