Turkey previously announced that its S400 air defense regiment would be activated and in service by the end of April, 2020, after its delivery from Russia in 2019. Since it is now May 2020, with no S400 deployment in sight, Aaron and Scott sat down with Rob Lee for an in-depth talk about what could be holding it up.  Rob Lee is pursuing his PhD at the Department of War Studies at King's College London. He was previously a Marine infantry officer and fellow at the Centre for Analysis of Strategies and Technologies (CAST).  Support us over at Patreon.com/acwpodcast!