The change is setting off debate in military legal-eagle circles. “A military accused isn’t accused of violating just any penal code,” argues a military attorney on a military-justice website. “He’s accused of violating the Uniform Code of Military Justice. In that context, I see his military character as indisputably `pertinent.’”

Others disagree. “Character evidence that a person is `law abiding’ or a `good citizen’ has long been prohibited in civilian courts,” a second poster maintains. “If you’re charged with raping your neighbor in federal court you don’t get to introduce evidence that you’re a `good father,’ `good carpenter,’ or a `good citizen’ under the theory that good fathers (etc.) are less likely to rape.”

The ability to present evidence that the accused is a good soldier has long been a valuable tool for military defense lawyers at courts-martial and other legal proceedings. The U.S. military justice system, by and large, has gone along. “Military courts are staunch supporters of such evidence as a relevant character trait to nearly every offense under the Uniform Code of Military Justice,” writes Army Major Rebecca Kliem on the Army’s staff judge advocate school’s blog, where she is an associate professor of criminal law.

“Given this expansiveness, imagination is the only limit of what demonstrates `good military character’; any desirable trait in a service member counts,” Army lawyer and Major Franklin Rosenblatt argued in the Army Lawyer journal in 2010. “In application, character witnesses are commonly called to testify about their willingness to deploy with an accused. Other allowable `good military character’ testimony includes that an accused is `dedicated to being a good drill instructor,’ lawful, easygoing, dependable, and well liked. With so many traits to choose from that are permissible and admissible, nearly anyone can qualify as a `good Soldier.’”

Nearly 20 years ago, an Army lawyer warned that the good-soldier defense could let the defendant’s attorneys “smother the fact-finder with good soldier evidence regardless of the charges.” And it tended to favor a certain kind of soldier, he noted: “The more senior the accused, the more likely the defense can craft some version of the good soldier defense.”

Four years later, the Army’s top enlisted soldier, Sergeant Major of the Army Gene McKinney, employed the good-soldier defense after he had been charged with sexually harassing women who worked with him. “McKinney’s adroit use of his past service as a `good soldier’ was widely credited for his acquittal on all charges of sexual misconduct, in spite of damning testimony from six servicewomen about his alleged harassment,” Elizabeth Hillman, now the president of the National Institute of Military Justice, wrote in 1999. “The good soldier defense advances the perception that one of the privileges of high rank and long service is immunity from conviction at court-martial,” said Hillman, now a professor of law and dean at the Hastings College of Law at the University of California.