"There's no question in my mind that the 15-month tours were very, very hard on our troops and on their families," Gates said during a Pentagon news conference. "And I think we moved to get back to 12 months deployed just as quickly as we could."
Gates said he hopes to see a lengthening of the "dwell time" at home stations between deployments for servicemembers in the near future.
"We won't go straight from one year deployed to two years at home; we'll more likely go from one year deployed to 15 months at home to 18 months at home and so on," Gates said.
"And I think with the growth in the end strength of both the Army and the Marine Corps, the drawdowns likely to come in Iraq, that we will see that situation improve over the next couple of years," he added.
The divorce and suicide rates and post-traumatic stress are indicators that the force is stressed. Gates said he believes those issues are related in part to repeated tours.
"It's not just the length of the tour, but the fact that so many have gone back for two and three and even four rotations in Iraq and Afghanistan," he said.
But the force is resilient, and the families strong and supportive, Gates said.
Marine Corps Gen. James E. Cartwright, vice chairman of the Joint Chiefs of Staff, who accompanied the secretary to the news conference, also noted the affects of tour lengths on servicemembers. Fifteen-month tours took a lot out of the force, and tours of that length just ended in August, he said.
"The cumulative effect is very important to understand, No. 1," he said. "And No. 2, we aren't done with the 15-month tours -- they're not home yet."
Cartwright pointed out the importance of understanding how servicemembers will be affected long-term. "What's the cumulative effect, how many of these tours, and when do we start to cross? Is it 15 months at home vs. a year deployed? Is it two years?
"We've got work to do there to understand this long-term," Cartwright said. "And we're watching this very closely."