Having served under both Presidents George W. Bush and Barack Obama, former Secretary of Defense Robert Gates has a unique understanding of presidential leadership. In his new book "A Passion For Leadership", Gates shares some of what he's learned in his 50 years of public service, including his tenure as the head of the Defense department.

On Hannity, Gates offered some insight into the mind and leadership of President Barack Obama.

"Bring me into the mind of the Barack Obama you knew," Sean asked Gates.

The former Defense Secretary said that he had two concerns about President Obama's style of leadership. His first concern was the president's "micromanagement". 

"[President Obama] seems to be unwilling to trust subordinates to execute his policies and so he centralized operational activities in the White House," Gates explained. "So, under previous administrations that I worked for, there might be 40 or 50 professionals on the national security council staff. There are now hundreds."

Gates' second concern was the president's inability to make a decision and execute it in policy. As an example, Gates pointed to the president's now infamous 2009 Cairo speech in which he declared a "new beginning" in U.S. mid-East relations.

"It led to a lot of euphoria and then nothing," Gates said. "There was no strategy, there was no implementation, and the result was bitterness in the Middle East because it was just seen as hallow rhetoric."

Watch Sean's interview with former Secretary of Defense Robert Gates on Hannity: