So, as Correspondent Scott Pelley first reported last fall, it's been drawing from a pool of semi-retired soldiers called the Individual Ready Reserve, and it's a sign that it needs able (and not so able) bodies to fill the gap.
Many of the men and women being mobilized in the Ready Reserve (9,000 so far) are not very happy about it. In fact, of those who were supposed to report to duty in April, nine out of 10 of them either applied for an exemption, or didn't respond at all.
But if old soldiers never die, as the saying goes, the Army isn't letting them fade away.
Many of those soldiers who have answered the call have come to Fort Jackson, S.C., for training. It's a place none of them really expected to be. In fact, very few expected to be mobilized at all.
"I automatically started crying for about two hours. I couldn't stop, because I knew I was gonna have to leave my babies," says Spc. Carey Trevino, who was called up in August.
She's 31, and has three kids; the youngest, a 7-month-old baby boy. She'll be leaving her children behind when she goes to Iraq for another year and a half.
"I need to serve my country and the call has come out, so I am doing that," says Chief Warrant Officer Margaret Murray, who did her active duty back in the '60s.
She's 55, and 4 feet, 8 inches tall. Her M-16 is almost as big as she is, but that didn't stop her from qualifying as a marksman this week.
Does she find it unusual that the Army is now calling up a female soldier in her 50s?
"No, although I think what they need to look at is our ability to perform in a tactical environment," says Murray. "For myself, I am going to find that a difficult thing to do physically."
Especially if Murray winds up in a place like Fallujah. Does she find that daunting? "Scary," says Murray. "[But] I need to do my job. … I did not retire. And so, now the Army's calling me back to service. And I'm here to do that."
There are 110,000 men and women in the Ready Reserve right now. They generally don't train or get paid or belong to units, but they can be called up in case of war or national emergency.
This already happened during the first Gulf War, when 20,000 Ready Reservists were mobilized for 120 days. But this time around, they'll be there for up to two years.
Pvt. George Sayegh is keeping his obligation as best he can. He may not look tough, but he is very tough on the guys who are not reporting for duty. "When you abandon your country in time of warfare, I feel that, knowing what your obligation is, I believe that it is an act of cowardice," he says.
But you'd be hard-pressed to call one woman 60 Minutes talked to a coward – even though she is resisting the call to return for duty. "Mary," as we're calling her, is a senior special agent with a federal law enforcement agency. She does undercover work in the war on drugs, which is why she appeared in disguise.
"You come up against a lot of big-time criminals. And they're prepared to kill and to shoot to get out of certain situations," says Mary, of her work in the war on drugs.
Is she reluctant to return to the Army because she is afraid of danger? "No, my reluctance is because what's right," says Mary. "I thought my time was up. And they're telling me that it's not."
Like many Army officers, Mary signed up for eight years, four years active duty, and four years in the Ready Reserves. She received her discharge certificate in 1998, but she was called up this past June to serve as a transportation officer.
"I called the Delay and Exemption Board. And the young lady that I talked to said that date [on my contract] meant nothing, that my new date is 2018," says Mary.
"I was in shock. I was like, 'What do you mean? I have a piece of paper that tells me that that's my obligation.' And for them to just send me orders and disrupt my life and pull me back, it's disheartening and I feel betrayed, I guess you could say. … The military is betraying me, because I served my time."
What Mary didn't realize is that, as an officer, she remained in the Ready Reserve, even after her eight years were through, because she hadn't resigned her commission as an officer.