Which political theory has been interpreted to mean that a president can shield critical information from congress as a result of the separation of powers?

It´s executive privilege.

Explanation:

The supporter of the president´s executive privilege say that he can shield sensitive information from Congress if there´s a risk to national security, or his acts to preserve US national security exempt him from legal liability, enjoying legal immunity.

the geography of greece

led to limited interactions with other cultures in the mediterranean

was rich in natural resources and led to repeated invasions from the macedonians

encouraged greater contact with peoples on the southern and eastern mediterranean coasts

caused the greeks to eventually relocate eastward under alexander the great