Women could begin registering for the draft as early as 2018, or the entire Selective Service System could be abolished by then.

Both options hang over upcoming negotiations connected to over the annual defense authorization bill, since House and Senate drafts of the policy measure contain dramatically different plans on whether women should be required to sign up for possible involuntary military service.

The Senate draft includes language that which would require all women between 18 and 26 to register with Selective Service officials. They argue in the legislation that "the ban of females serving in ground combat units has been lifted by the Department of Defense Department, and as such, there is no further justification to apply the selective service act to males only."

House lawmakers at one point had similar language in their authorization bill draft, but stripped it out during floor debate last month. Instead, they favor a report on the possibility of eliminating the Selective Service agency, amid comments from critics that it has outlived its usefulness.

The system costs about $23 million a year to maintain, even though it hasn’t been used in more than five decades. And a 2012 report by the Government Accountability Office called into question whether officials with the system could supply a list of draftees if the Defense Department asked for one, citing given shortcomings in the process.

House and Senate Armed Services Committee leaders met Thursday to discuss potential sticking points in upcoming conference discussions on a compromise authorization bill.

Senate committee chairman John McCain, R-Ariz., said he didn’t see the issue as a major point of contention, even though several senators fought unsuccessfully to strip the women registration change from the bill.

Committee ranking member Jack Reed, D-R.I., went even further.

"I think it's important to include that" in the final version, he said. "Women have demonstrated superb skill in every aspect of military operations, and I think this is just a recognition of their contributions to the military. So I hope it's not a major fight."

The proposed House study on the Selective Service issue would include an analysis not just of ways to restructure the system, but also whether such changes "would impact the need for both male and female inductees."

That plan was backed by House Armed Services Committee Chairman Mac Thornberry, R-Texas., in drafting the bill and on the House floor. He said he's open to other ideas on the issue as the conference looms, but "I still think that we ought to study whether we need it or not before we get to the question of who should be registered."

In an U.S. News editorial this week, a pair of leaders from Service Women’s Action Network argued for including women in future military drafts.

"If women meet existing high standards for service and enjoy all of the benefits of citizenship in time of peace, they must be equally responsible for defending the nation in a time of war," the editorial states. "We cannot expect full equality if we continue to support a Selective Service that only requires compulsory service by men."

But the idea has received strong opposition from a number of Republican lawmakers, including several presidential hopefuls during the spring primary season.

RThe idea of registering women for possible military service for the first time would represent a historic change for the country, even if it’s largely symbolic. Military leaders have repeatedly said they have little desire to return to compulsory service to fill the ranks, saying today’s all-volunteer force is better trained and more better motivated than any before it.

Conference committee work won’t officially start for a few more weeks and is expected to stretch through Congress’ lengthy summer break. A final decision on the draft issues and the overall authorization bill isn’t expected until the later this fall.  

Leo Shane III covers Congress, Veterans Affairs and the White House for Military Times. He can be reached at lshane@militarytimes.com.