for the second time in a little more than two years, an isis leader is dead after an american air strike. in 2019 it was abu bakr al baghdadi. this time it was abu ibrahim al hashimi. he blew himself up, also killing his wife and children. national security analyst peter bergen, author of "the rise and fall of osama bin laden," also mark hertling, former commander of the u.s. army in europe. peter, how effective are strikes like these in crippling a group like isis? >> well, i mean, if you look at the taliban, anderson, president obama ordered a strike on mullah