The non fiction book The Way of the Knife The CIA a Secret Army and a War at the Ends of the Earth was written by which author?

Introduction / Context:
The Way of the Knife The CIA a Secret Army and a War at the Ends of the Earth is a detailed work of investigative journalism about modern warfare, intelligence agencies and covert operations. Questions on this book appear in general knowledge and current affairs exams because it deals with contemporary security issues and American foreign policy. Identifying the author as Mark Mazzetti shows awareness of important journalistic works on the war on terror.

Given Data / Assumptions:

• The full title given is The Way of the Knife The CIA a Secret Army and a War at the Ends of the Earth.
• The options list several writers, some of whom are associated with fiction and others with political themes.
• The question asks which author wrote this particular non fiction work on intelligence operations.
• We assume the book refers to the widely known piece of investigative journalism published in the last couple of decades.

Concept / Approach:
To answer, we need to distinguish between authors of literary fiction and journalists who write contemporary non fiction. Mark Mazzetti is an American journalist who has reported extensively on national security for a major newspaper and wrote The Way of the Knife, which examines how the Central Intelligence Agency and the military shifted toward targeted killings, drones and covert operations. In contrast, Mark Twain and Mario Puzo are fiction writers from different eras, and John le Carre is primarily a spy novelist, not the author of this particular factual account.

Step-by-Step Solution:
Step 1: Read the complete title and note that it refers to the CIA, a secret army and war at the ends of the earth, indicating a serious work on intelligence and security. Step 2: Recall that Mark Mazzetti is a journalist known for covering the war on terror and writing extensively about drone warfare and covert operations. Step 3: Remember that The Way of the Knife is one of his major books on how warfare has transformed into targeted killing and surveillance. Step 4: Cross check the other names: Mark Twain wrote humorous novels and classics like The Adventures of Tom Sawyer, Mario Puzo wrote The Godfather and John le Carre wrote fictional spy novels such as Tinker Tailor Soldier Spy. Step 5: Conclude that only Mark Mazzetti is consistent with the subject and known authorship of this book.

Verification / Alternative check:
You can verify by recalling media references to drone warfare and covert operations books. The Way of the Knife is frequently cited in articles on the evolution of the CIA and special operations, often mentioning Mark Mazzetti by name. In contrast, Mark Twain and Mario Puzo belong to earlier periods and are linked to very different genres. John le Carre did explore intelligence themes, but mostly through fiction, and none of his novels carry this exact title. This reinforces that the non fiction analysis of the CIA mentioned in the question is by Mark Mazzetti.

Why Other Options Are Wrong:
Mark Twain was a nineteenth century American novelist and humorist whose works do not cover modern intelligence agencies. Mario Puzo wrote crime and mafia novels, most famously The Godfather, rather than detailed journalistic accounts of the CIA. John le Carre created fictional stories about spies and espionage but is not the author of this specific non fiction book.

Common Pitfalls:
One common error is to choose John le Carre simply because he is associated with spy stories, even though he writes fiction, not this journalistic study. Another pitfall is to be distracted by the familiar sounding name Mark Twain, which is unrelated to modern security topics. To avoid such mistakes, candidates should remember that many key works on intelligence and covert warfare are written by investigative journalists, and Mark Mazzetti is one of them for this particular title.

Final Answer:
Therefore, the book The Way of the Knife The CIA a Secret Army and a War at the Ends of the Earth was written by Mark Mazzetti.