Related Topics: September 11 AttacksUnited StatesTalibanSpecial Activities DivisionOsama Bin LadenGeorge W. BushVideos of Osama Bin LadenTerrorismIslamic TerrorismIslam
The U.S. has been helping to fight terrorism in the African nation since 2013.
Authorities are urging people who may have more information to come forward.
The ad is a sign Republicans are nervous about their chances in an upcoming special election.
Trump declined to name any specific examples.
Michael "Duke" Lowrie is standing by a Facebook post from 2015.
The lack of a "long-term strategy that has been effective ... should scare us," says Brookings senior fellow Shadi Hamid.