I don't know why it's so difficult to understand the difference between port security and port ownership.
Simple: they don't want to know.
Would you mind the UAE owning a nuclear power plant here in the US if Americans still provided the security?
See, by TREATY and Law, DP World will be involved with DHS/Coast Guard Security, in planning, in SOP's, in Plans of Action.
Oh, and DP World will also oversee 2 MILITARY Ports in Brownsville and Corpus Christie Texas. These Ports are where Mercahnt Marine and other military and NON-Military would be involved in Military movements of Heavy equipment...JUST what our enemies would LOVE a heads-up on.
THAT is why they will be involved in security, and why this is a BAD idea!