FISA IS NOT WHAT DETERMINES EXECUTIVE POWERS.
"The Constitution designates the president as commander in chief, and Congress can no more direct his exercise of that authority than he can direct Congress in the execution of its constitutional duties. As the FISA court itself noted in 2002, the president has "inherent constitutional authority to conduct warrantless foreign intelligence surveillance."
Horrid logic. Congress is given the power to make rules for the government. The President is given no such corresponding power.
And as for any magical aura of protection supposedly emanating from the term "commander in chief", here is the commission that the Continental Congress bestowed upon General Washignton during the war of independence. After appointing him "General and Commander in chief, of the army of the United Colonies", the commission made it clear that "you are to regulate your conduct in every respect by the rules and discipline of war, (as herewith given you,) and punctually to observe and follow such orders and directions, from time to time, as you shall receive from this, or a future Congress of these United Colonies, or committee of Congress."
Obviously the founders did not view the status of "commander in chief" as being inconsistent with taking orders from a council, any more than the status of captain of a ship is inconsistent with taking orders from an admiral. And if it's not inconsistent with taking orders from a council, it's certainly not inconsistent with obeying laws passed by a legislative body that's given express power to make rules for the government.