He can't authorize the assassination of anyone. Remember the Church Commission and Jimmy Carter? It's illegal. Another one we owe to Jimmy and the Democrats. Bomb a Mosque and give them another excuse to whip up the fanatics. I understand your frustration, but he can;t always do what he wants. I'm sure there are times when the President has just wanted to say "the Hell with it, lets just nuke Iran & Iraq and get it over with. Unfortunately, life isn't that simple. Wish it were.
Nope it was Gerald R. Ford the Church Committee was in era 1975-76 who by E.O. in 1976 that made the covert assassination of others verboten. Carter however did sign one just like it as did Reagan. The difference? Reagan did not hesitate to launch a military strike to accomplish the same task.
Excerpted information from http://en.wikipedia.org/wiki/Church_Commission #The_Ford_administration_and_the_Church_Committee
In 1975 and 1976, the Church Committee published fourteen reports on the formation of U.S. intelligence agencies, their operations, and the alleged abuses of law and of power that they had committed, together with recommendations for reform, some of which were put in place. Among the matters investigated were attempts to assassinate foreign leaders, including Patrice Lumumba of the Congo, Rafael Trujillo of the Dominican Republic, the Diem brothers of Vietnam, Gen. René Schneider of Chile and President John F. Kennedy's plan to use the Mafia to kill Fidel Castro of Cuba. Under recommendations and pressure by this committee, President Gerald Ford issued Executive Order 11905 (ultimately replaced in 1981 by President Reagan's Executive Order 12333) to ban U.S. sanctioned assassinations of foreign leaders. Together, the Church Committee's reports have been said to constitute the most extensive review of intelligence activities ever made available to the public. Much of the contents were classified, but more than 50,000 pages have since been declassified under the 1992 JFK Assassination Records Collection Act.
I know it's a Wikipedia source but I am sure on this as I have looked it up several times in other sources. You have to remember that politically Ford and Carter were pretty much the same. Many of the Ford woes spilled over into Carters term including the military ones. True Carter was horrible but this one was done by Ford. Carter just signed off on it.