THE HOPE that Congress would adopt bold measures to end the epidemic of sexual abuse within the military seems headed for the same heap of broken promises that has accompanied each new scandal over decades. Disappointing moves in the House and Senate last week failed to address the core issue of a biased chain of command. Unless there’s a change of heart — or action by a commander in chief who claims to want results — unwanted sexual contact and assaults in the ranks will continue to go unreported and unpunished.

Legislation that would have taken decisions about sexual assault cases out of the chain of command and placed them in the hands of independent prosecutors was killed Wednesday in a Senate committee; the House refused even to discuss the matter. The Senate Armed Services Committee was the scene of an emotional debate as supporters of the measure, which had bipartisan support, pointed to the abject failure of military officials — dating to the first publicly known scandal in 1991 — to fix the problem.

Sen. Kirsten Gillibrand (D-N.Y.), lead sponsor of the measure, offered vivid testimony of why military sexual assault victims don’t trust the current system. “The assailant is usually someone senior to them, someone up the chain, someone senior, more decorated, Purple Heart recipient, someone who has done great acts of bravery and they see that the chain of command will not be objective.” Of the 26,000 unwanted sexual contact incidents in 2012 contained in a recent Defense Department survey, only 3,374 were reported and, Ms. Gillibrand said, only one in 10 ended up going to trial.

The committee nonetheless sided with military brass who had vigorously opposed this loss of command authority. Sen. Carl Levin (D-Mich.), chairman of the committee and leader of the effort against Ms. Gillibrand’s legislation, argued that the proposal would have weakened the response to sexual assault . He offered a series of measures, approved by the committee, that aim to protect victims by making retaliation a crime and providing review of decisions in which commanders don’t follow recommendations to prosecute from military lawyers under their supervision.

Tweaks to the current system are fine, but they are a far cry from the fundamental change that is needed. The results of Mr. Levin’s actions will be to support a status quo that should be recognized as unacceptable.