. >> colonel dede halfhill: sometimes i'll say "have you heard of brenÉ brown?"e kind of walk you through this." >> whitaker: air force colonel dede halfhill, who's currently the spokeswoman for the chairman of the joint chiefs of staff, first encountered brenÉ brown's work when she was a squadron commander in iraq. she's now been trained and certified to teach brown's techniques to other military officers. >> colonel halfhill: society is changing. and what society needs from its leaders is changing. it needs leaders who can have really hard conversations around things like race, sexual assault, suicide. so to say you get to be a leader who doesn't talk about feelings, that's not possible anymore. >> whitaker: i can hear people saying, "an-- an officer in the air force, someone who's, you know, fighting a war, is not supposed to feel vulnerable. you're not supposed to talk about your feelings." >> colonel halfhill: vulnerability is the birthplace of courage. and courage is not doing something because you're fearless. courage is doing something because you may be