Logically, Bush could just decree it.

Consider:

• President Bush argues that we are at war (against "terror"), that the war will go in indefinitely, and that he alone decides what constitutes a cessation of conflict.
• President Bush argues that the executive branch has what amounts to absolute power on matters of national security during wartime, irrespective of statute and without Congressional oversight.
• President Bush argues that making the U.S. independent of "foreign oil" is an issue of national security.
• President Bush argues that drilling in the Arctic Refuge could help make the U.S. independent of foreign oil.

Given the above, why can’t Bush just decree that the Arctic Refuge will be opened to drilling?