Gates: 'We Make a Lot of Wrong Assumptions About War'

By Susan Jones | January 15, 2014 | 5:24 AM EST

Robert Gates and President Obama at Gates's farewell ceremony. (AP File Photo)

( - Robert Gates, who served as Defense Secretary under Presidents George W. Bush and Barack Obama, says Americans need to ask more questions -- and presidents need to provide more clarity about their objectives -- when the country goes to war.

"[W]hat I believe is that we make a lot of wrong assumptions about war. And too often, the questions about what happens if those assumptions are wrong are never asked," Gates told Fox News's Sean Hannity Tuesday night.

"For example, we go in -- we went into both Iraq and Afghanistan believing that these would be short wars. The American people are fine with a war, like the first Gulf war, that lasts 100 hours, with a couple of months of bombing beforehand.

"But any president that puts the United States -- puts American military into a situation where we're using force without clear objectives, without clear guidelines in terms of what -- what do we hope to achieve here and what are our benchmarks in terms of whether we're being successful -- when president -- the first President Bush launched the Gulf war, the only time in my experience he actually put down on a piece of paper what our war aims were. And we would stop when we achieved those aims."

According to Gates, "We need clarity from our political leaders, from presidents, when we do use military force so that we don't get sucked into long, grinding conflicts like we faced both in Afghanistan and Iraq and where you end up with ambiguous outcomes."

As for the lessons of Iraq and Afghanistan, Gates said that when wars drag on, political and public support tends to evaporate. "And so we have to be more careful about when we engage our military force so that when we do, we can accomplish our objective fairly quickly and then come home."

Gates's new book "Duty," released on Tuesday, has made him a fixture on news shows for the past two weeks.