WASHINGTON -- The decision by the Pentagon to allow women to serve in all combat jobs has put new focus on an often-forgotten U.S. institution: the Selective Service. While America has not had a military draft since 1973, all men must register with the Selective Service within 30 days of turning 18. U.S. leaders repeatedly insist that the all-volunteer force is working and the nation is not returning to the draft. But there are increasing rumblings about whether women should now be required to register if they can indeed serve in all areas of the military. Some questions and answers about the Selective Service and any moves toward requiring women to register:Q: Is the Selective Service part of the Defense Department? A: No. It is an independent agency that exists to ensure that the nation would be able to force men into military service in a fair and equitable way if directed by the president and Congress in a national crisis.Q: Are women subject to the draft? A: No. Under the current law, women can volunteer to serve in the U.S. military, but they are not required to register and they would not be subject to any draft.Q: Has the law been challenged? A: Yes. In 1981, the Supreme Court heard a case brought by several men challenging the law for gender discrimination. The court upheld the constitutionality of the male-only draft registration law. The court accepted Congress' decision to exclude women from registration because they were excluded from direct combat by statute and by military policy.Q: Who would decide if women need to register? A: It would take an act of Congress. Recently four U.S. House members introduced legislation to abolish the Selective Service, saying that the all-volunteer force is working. And two members of Congress introduced legislation requiring women to register but said they actually opposed their own bill. They said they were only doing so to trigger a debate on allowing women to serve in front-line combat jobs -- which they also oppose.Q: What does the Pentagon say? A: When Defense Secretary Ash Carter decided to open all combat jobs to women, the Defense Department did a legal analysis of his decision. The analysis found the landscape has changed since the court case, and that opening combat jobs to women "further alters the factual backdrop to the Court's decision." The Pentagon had made no recommendation on the matter, but the department said it will consult with the Justice Department when needed.Q: Do military officials and politicians believe women should register? A: During recent hearings, the Army's chief of staff, Gen. Mark Milley, and the commandant of the Marine Corps, Gen. Robert Neller, said they thought women should have to register. Some key lawmakers, including Republican Sen. John McCain, chairman of the Senate Armed Services Committee, agree. Republican presidential candidates Sen. Marco Rubio and former Gov. Jeb Bush said they supported the idea of having women register. Republican Sen. Ted Cruz said later that including women would be "nuts" and a dangerous example of political correctness.Q: What penalties are there if an 18-year-old doesn't register? A: If an 18-year-old man does not register with the Selective Service he could lose his eligibility for student financial aid, job training and government jobs. Immigrant men could lose their eligibility for U.S. citizenship. According to the latest annual report, 73 percent of 18-year-olds registered on time in the 2015 fiscal year ending last Sept. 30. And, the registration rate for all men aged 20-25 was 94 percent.