The Pentagon struck a blow for both military preparedness and sex equality Thursday by opening all combat jobs to women. Allowing female troops who meet the same standards as men to fight the enemy improves a nation’s ability to protect itself and its foreign interests.

But as the military takes this big step toward equal treatment of men and women, it inevitably comes up against a next one: the need for equality in Selective Service registration. Fair treatment demands that young women — ages 18 to 25 — be required to sign up.

Men have to register within 30 days of their 18th birthday, even if they’re disabled or for any other reason would not realistically be suited for active duty. Failure to do so is a felony, and while prosecution is rare, it can mean ineligibility for federal jobs and benefits, college loans and driver’s licenses.

The United States hasn’t had a draft since 1973, and despite major wars in Afghanistan and the Middle East, has never come close to reinstating it. But the Selective Service requirement remains essential to keeping the United States prepared for the unthinkable. Should a larger military be required, it’s important to have a registry of all potentially eligible participants.

Few countries have active conscription of women. Israel has long been an exception, and women are drafted in Bolivia, Chad and (not the best example) North Korea. Next year, Norway, a NATO member, will make women serve 19 months, just as men do.

But the U.S. needs no foreign precedents. In recent decades, American women have demonstrated their ability to serve throughout the military. They now make up 15 percent of active forces and 23 percent of new officers. Last summer, two women graduated from the Army’s rigorous Ranger School. And they’ve made extreme sacrifices: In Iraq and Afghanistan, more than 100 have been killed and nearly 1,000 wounded.

Given this new reality, Air Force Secretary Deborah James has said she has no objections to requiring women to register. Army Secretary John McHugh said it is a matter of “true and pure equality.”

No female draftee, if it came to that, would be forced onto the battlefield, just as female enlistees will not be. Decisions about exactly what female conscripts would do need not be made ahead of time. All that’s needed now is to acknowledge that, when it comes to military service, women should have the same opportunities — and responsibilities — as men.

Editorial by Bloomberg View