In an article written for The Washington Post, a more moderate-sounding US Defence Secretary argued the challenge is "to stop the next generation of terrorists from forming."
Hitherto known for his strong advocacy of pre-emptive strikes and the wars in Iraq and Afghanistan, Rumsfeld surprisingly struck a conciliatory note and instead stressed on winning the war of ideas as well.
"For every terrorist whom coalition forces capture, kill, dissuade or deter, others are being trained," the secretary of state wrote.
"To win the war on terror, we must also win the war of ideas –the battle for the minds of those who are being recruited by terrorist networks across the globe."
Rumsfeld's turnaround comes amid growing scepticism over the US-led war in Iraq.
He has argued it is critical for Americans to recognise that the war on terrorism "will be long, difficult and dangerous," and as the military deals with the immediate terrorist threats, "we also need to find ways to stop the next generation of terrorists from forming."
"To win the war on terror, we must also win the war of ideas"
US Secretary of State
Pondering lessons of a 1983 attack on the US Marine barracks in Beirut that left more than 240 US troops dead, Rumsfeld said building concrete barricades across buildings and surrounding them with wire fences could hardly be the answer because "for every defence, the terrorists moved to another avenue of attack."
"Terrorists have a sizeable advantage," Rumsfeld wrote. "A terrorist can attack any time, in any place, using virtually any technique. And it is not possible to defend every potential target at all times in every place against every form of attack."
"The task is to stop terrorists before they can terrorize," the secretary of state said. "And even better, we must lean forward and stop them from becoming terrorists in the first place," he wrote.