The proposed amendment to National Defense Authorization Act would create an independent judicial system to investigate reported sexual assault.

In short, Grassley stood up for women who, too often, are twice victimized: Once by a peer and again by an institution that favors machismo and public relations over justice. His justifiable anger followed an inspector general’s report that detailed an instance where a female officerreported being raped and was greeted by a career-scuttling evaluation by her commanding officer, Brigadier General Charles Viet.

“This is a perfect example of why it needs to come out of the chain of command and set up a separate prosecution unit for these rapists,” Grassley told reporters last week.

We share his rage.

Five percent of women and 1 percent of men in the Armed Forces — some 20,000 soldiers, sailors and airmen — reported a sexual assault in 2013, says a study conducted in 2014 by Sen. Kirsten Gillibrand’s office. Of 329 cases sampled, just 22 percent went to trial and conviction rates were flirting with single digits.

Clearly, justice is of no concern to the generals, and they’ve proven unworthy of the investigatory oversight the system now permits.

Politically, Grassley’s unequivocal support is a significant boost for the long-languishing amendment. Gillibrand, D-New York, has for years pushed the overhaul of the secretive, victim-blaming military justice system. But her minority status and a general unwillingness among congressional Republicans to condemn the military has doomed it to the dust pile.