In an appearance on “CBS This Morning” on Wednesday, former Defense Secretary Robert Gates, who served in both the Obama and Bush administrations, argued that in order to achieve objectives to destroy the threat of ISIS, including Vice President Joe Biden’s statement to “follow them to the gates of hell,” will require ground forces despite arguments otherwise.

“The reality is, they’re not going to be able to be successful against ISIS strictly from the air, or strictly depending on the Iraqi forces, or the Peshmerga, or the Sunni tribes acting on their own,” he said. “So there will be boots on the ground if there’s to be any hope of success in the strategy. And I think that by continuing to repeat that [the U.S. won’t put boots on the ground], the president, in effect, traps himself.”

“I’m also concerned that, the goal has been stated as degrade and destroy, or degrade and defeat ISIS,” Gates added. “We’ve been at war with al Qaeda for 13 years. We have dealt them some terrible blows including the killing of Osama bin Laden. But I don’t think anybody would say that after 13 years we’ve destroyed or defeated al Qaeda. And so I think to promise that we’re going to destroy ISIS, or ISIL, sets a goal that may be unattainable, as opposed to devastating it, or whereas the vice president would put it, ‘following them to the gates of hell’, and dealing them terrible blows that prevent them from holding territory. Those are probably realistic goals.”

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