At a breakfast meeting with reporters, Gen. James Conway also warned that it could take years to adequately train and equip the Iraqi security forces — longer, perhaps, "than the timeline that we probably feel ... our country will support."
"This is tough work, it doesn't happen overnight," and patience by the American people will be needed, he said. On the plus side, he said Marines he's talked to in recent days are encouraged by the progress they are seeing among Iraqi forces.
Conway said the current pace of Marine rotations to Iraq — seven months there and seven-to-nine months at home — is limiting other types of training that units can receive and could eventually prompt Marines to leave the service.
"There is stress on the individual Marines that is increasing, and there is stress on the institution to do what we are required to do, pretty much by law, for the nation," said Conway.
The goal, he said, is for units to spend twice the amount of time at home as is spent on deployment — for example seven months deployed and 14 months at home.
At the same time, Conway would not rule out extending the Iraq tours for some Marine units if needed for a short period of time. Several Army units have been extended for several months, but the Marines have done that only rarely and for weeks rather than months.
Conway, who took on the Marines' top job just eight days ago, said there are two ways to deal with the ongoing stress on the Marines: "One is reducing the requirement, the other is potentially growing the force for what we call the long war."
The Bush administration is finalizing the budget for fiscal 2008, which starts next Oct. 1, and the armed services are hoping to receive increased funding to carry on the fighting. Conway said he could not say how much the Marines would be seeking.
There are currently about 180,000 active duty Marines. Just last week, the top U.S. commander in the Middle East said about 2,200 more of them were headed to Iraq's volatile western Anbar province in a short-term effort to shore up U.S. combat power there.
The commander, Gen. John Abizaid, also told Congress last week that the Army and Marine Corps are not big enough to sustain a substantial increase in Iraq, although he said adding 20,000 troops for a short period was possible.
Conway said that if a decision is made to increase the number of Marines in Iraq — currently about 23,000 of the 141,000 U.S. troops there — he has enough around the globe to respond. But he warned that there could be long-term repercussions.
"The payback is you can't maintain that surge. And it's probably going to have an adverse impact" on the ability to provide ready troops in the future, he said.
Increasing the size of the Marine Corps, he added, could only be by 1,000-2,000 troops per year over an extended time. And if the size is increased to meet the needs of war, Conway said there would have to be a plan for reducing the numbers when the war is over. He said the current 180,000 level is the right size for peacetime.
The Marines are also drawing up plans to send some reserve combat battalions back to Iraq for return tours as a way of relieving the strain on the active duty forces. If that is done, it would be the first time such Marine units would be returned to the war.