Sen. Kirsten Gillibrand has proved a number of things in her important and honorable battle to protect women in the armed services. One of them is this: She knows how to fight.

Gillibrand came out on the losing end of her battle to wrest control over prosecution of sexual assaults away from the chain of command, in favor of trained prosecutors. But she raised the profile of the issue enough that when – not if, but when – it’s shown once again that commanders aren’t up to confronting this critical issue, she will be all but unstoppable.

The most frustrating aspect of last week’s vote is that a majority of senators supported the bill. Fifty-five of the chamber’s 100 members backed the measure, including 10 Republicans. But because of a filibuster threat, the legislation required 60 votes and it fell short.

Earlier this week the Senate unanimously approved a watered-down measure that would force a half-dozen changes in military law concerning rape and sexual assault within the ranks.

The legislation may be useful, but any bill that leaves the command structure in control of who is prosecuted and who is not – as this bill does – will fall short.

Opposition to Gillibrand’s bill was dressed up in patriotism and defense readiness, but the excuses don’t hold up. For example, Sen. John McCain, R-Ariz., argued that taking authority away from commanding officers would somehow undermine them and even compromise the ability to fight.

What does he think it does when sexual assaults go ignored, downplayed and unprosecuted? What does he think it does to military readiness when victims of sexual assaults don’t report them because of their lack of confidence in a rotten system?

Military commanders have been promising for years to clean up the system, but commanders, themselves, have been sexual abusers. Nothing changes. That’s why Washington has to act, and Gillibrand’s approach remains the correct one.

Other countries have already wrested authority over sexual assaults from the chain of command. Britain, Canada, Israel and other countries found that the system to which the United States unaccountably clings mistreats the victims of assaults. The militaries of those countries, by all accounts, are still functioning well.

This dispute is about an unwillingness to confront the reality of sexual assault in the military and the unwillingness of the brass to respond appropriately. As Sen. Charles E. Grassley, R-Iowa, observed regarding the military’s failure to deal with the problem despite repeated promises: “Enough is enough.”

After this week’s vote, Sen. Jeanne Shaheen, D-N.H., who backed Gillibrand’s effort, said: “I know that all the women senators will be monitoring this issue closely to ensure there are real improvements in the way sexual assault is reported and prosecuted in the future.”

If not, the matter is almost certain to come back before the Senate. At that point, Gillibrand says, a number of senators currently opposed have promised to support her approach.

She should keep pushing.