Calling for arrests before they are ready for them is foolish. The mob in NYC got taken down in one day, but it took years to get everything lined up.
How are they going to start arresting people when they don't know who all the bad guys are yet? Every time there is some sort of shooting or bombing dirty FBI is all over it. My take is the powers that be are wary of the Marshal service as well as the FBI.
Gitmo upgrades were said to have to be finished by 3/31/18