A President cannot confer such authority by an Executive order. In fact, when the military criminal investigative authorities were created back in the 80s, there had to be legislation passed before even Federal agents had the authority to effect arrest.
Some EO have the full force of law, others do not - those are just administrative orders issued to the executive branch. For a EO to have full force of law, the Congress must pass legislation that allows a President to exercise such authority.
While I'm interested to read the rest of this order, I'm much more inclined to believe it either expands or limits US oversight into the international organizations themselves, while they operate on or are domiciled on US soil. But, arrest on American soil - even of non-Americans by foreign authorities, isn't something that this President or any President can approve.
The perfect sortie is when they never see it coming, never know what hit 'em, and never see the evac; like they got hit by a ghost. A real hard, snake eating ghost.
Ah, the good old days... I never thought we'd need to revive the stealth tactics back here in the world. Hmmmm... now where did I put that ghillie...?
;-/