The Republican lawmakers from Arizona and South Carolina made the comments Monday during a town hall meeting at The Citadel, South Carolina's military college.
The war was discussed, but the meeting centered mainly on health care. Graham said some Citadel cadets will find themselves on the front lines in coming years.
Defense Secretary Robert Gates is expected to ask for additional forces to handle a rising threat from roadside bombs in Afghanistan. But the White House has said no decision is expected for weeks.
Graham said the war is not Obama's war but America's war and the nation must win it.
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