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US Navy Admiral Leahy : “The Second Most Powerful Man In The World”

US Navy Admiral Leahy : “The Second Most Powerful Man In The World”

World War 2
As governor of Puerto Rico in 1939

Fleet Admiral William D. Leahy

Although most people have never heard of him, Fleet Admiral William Leahy has been called “the second most powerful man in the world” due to his position as President Franklin D. Roosevelt’s principal military advisor during World War II. He served as FDR’s (and eventually President Harry Truman’s) “Chief of Staff to the Commander in Chief,” and the de facto Chairman of the Joint Chiefs of Staff (JCS) and the Combined Chiefs of Staff (CCS). He was also the first officer promoted to the five-star, Fleet Admiral rank.

Leahy was born in Hampton, Iowa in 1875. He graduated from the United States Naval Academy in 1897 and began his naval career as a midshipman on the USS Oregon. Admiral William D. Leahy married Kathryn McNulty Leahy, with whom he had two children, William D. Leahy Jr. and Kathryn Leahy Smith. William D. Leahy Jr. followed in his father’s footsteps and served as a naval officer, eventually reaching the rank of Rear Admiral.

Admiral Leahy

He served in various positions throughout his naval career, including as a gunnery officer, a navigator, a commander of a destroyer division, and a commander of a cruiser division. As a young ensign, he supported operations in the Philippines during the Spanish-American War, the occupation of Haiti in 1915, and the occupation of the Dominican Republic in 1916. In addition, Leahy befriended and served in key roles where he worked hand-in-hand with then-Assistant Secretary of the Navy Franklin Roosevelt from 1913 to 1919. Roosevelt would maintain this friendship and be a key mentor for Leahy throughout the rest of his career. During World War I, he was awarded the Navy Cross for commanding a troop ship that braved the German U-Boats in the North Atlantic.

From 1937 to 1939 Admiral Leahy served as the Chief of Naval Operations (CNO), the highest-ranking officer in the United States Navy. As CNO he worked diligently to ensure the passage of the Second Vinson Act (sponsored bey Senator Carl Vinson) in 1938, which included a 20% increase in the construction of all classes of warships. This resulted in the building of four more Iowa-class battleships, five Montana-class battleships, five aircraft carriers, and 24 Cimarron class oilers, which would be crucial for projecting American sea power across the Pacific.

Leahy retired from the Navy in 1939 and served as the Governor of the Territory of Puerto Rico and then Ambassador to Vichy France.

After the bombing of Pearl Harbor, Leahy was recalled to active duty. He was appointed as the Chief of Staff to the Commander in Chief, a position that made him the chief military advisor to President Franklin D. Roosevelt. In this role, he was present at many of the key Allied conferences and meetings, including the Casablanca Conference, the Tehran Conference, and the Yalta Conference. He also attended the Potsdam Conference, where he advised President Harry S. Truman. Leahy was one of the few people who knew about the atomic bombings of Hiroshima and Nagasaki before they occurred.

He died in 1959 at the age of 84. For more on Leahy, you can read his autobiography of his World War II experiences entitled I Was There: The Personal Story of the Chief of Staff to Presidents Roosevelt and Truman: Based on His Notes and Diaries Made at the Time (which is exceptionally dry) or Phillips O’Brien’s The Second Most Powerful Man in the World: The Life of Admiral William D. Leahy, Roosevelt’s Chief of Staff.

How Admiral Leahy Ran the War

Fleet Admiral William D. Leahy, known for his strong leadership style and his ability to effectively manage and coordinate the efforts of the military and civilian leaders during World War II, supervised the conduct of World War II through three meetings: the daily meeting with FDR, the weekly JCS meeting, and the weekly CCS meeting. This was Leahy’s battle rhythm or what the US Army defines as the “deliberate daily cycle of command, staff, and unit activities intended to synchronize current and future operations.” You can read more on battle rhythm here.

Operating from an office in the East Wing of the White House, he used a small personal staff of two military aides-de-camp and two or three secretaries to help him. Leahy usually arrived at his White House office between 8:30 and 8:45 AM each day and went over copies of dispatches and reports, including Ultra intelligence. For convenience, the documents were color coded: pink for incoming dispatches from the theater; yellow for outgoing ones; green for JCS papers; white for CCS ones; and blue for papers from the Joint Staff Planners. Leahy would select the papers to be brought to the President’s attention, and would meet with him each morning in the Oval Office or the Map Room when Roosevelt came to work.

Every Wednesday at noon Leahy chaired the meeting of the Joint Chiefs of Staff (JCS). The other members were General George C. Marshall, Chief of Staff of the US Army; Admiral King, Chief of Naval Operations and Commander in Chief, U.S. Fleet; and Lieutenant General Henry H. Arnold, the Chief of U.S. Army Air Forces. He drew up the agenda for the JCS meetings, presided over them, and signed off on all the major papers and decisions.

JCS Meeting and Lunch, 1943

Leahy also chaired the every Friday meeting of the Combined Chiefs of Staff (CCS). In these meetings the JCS (Leahy, Marshall, King, and Arnold) met with the leaders of the British Joint Staff Mission: Field Marshal Sir John Dill, Admiral Sir Andrew Cunningham, Air Marshal Douglas Evill and Lieutenant General Gordon Macready. Leahy also drew up the agenda for the CCS meetings, presided over them, and signed off on all the major papers and decisions.

Application Of Leahy’s Principles

President Roosevelt and Admiral Leahy

Also, it is worthwhile to revisit your company’s battle rhythm. If Admiral Leahy could create the strategy for 16,000,000 military members deployed around the globe fighting Germany and Japan using three meetings, what are your three most important meetings? What are your least useful meetings and should be discarded?

Sitting (from left): Clement Attlee, Harry S. Truman, Joseph Stalin; behind: William D. Leahy, Ernest Bevin, James F. Byrnes and Vyacheslav Molotov.

Review your company’s last six months of meetings by opening up your calendar and making a list or each weekly, bi-weekly, monthly, quarterly, and annual meeting that happened. Once you have your list of all the meetings that happened, then expand the list by adding the attendees, the purpose of the meeting, and any outcomes from the meeting. Once you’ve reviewed six months of meetings you will have a pretty good understanding of your company’s battle rhythm.

After you have your arms around all the meetings that happen, you can evaluate how successfully or poorly your meetings help the company achieve its purpose. Is each meeting helping us achieve our purpose? Is each meeting helping us achieve our end state (what success looks like at a certain date in the future)?

Keep the meetings that help drive the organization forward, discard those that don’t, and add new ones, if necessary. As you design your new battle rhythm, a general rule of thumb for corporate meetings purpose and length:

  • Annual meetings: Set targets and strategy (1-2 days)
  • Quarterly meetings: Review results and adjust the strategy (.5 – 1 day)
  • Quarterly team building meetings: Build the team (2-3 hours)
  • Monthly meetings: Check and correct deviations (2–3 hours)
  • Weekly meetings: Track and monitor execution (1 hour)
  • One-on-one meetings: Communicate from supervisor to employee and from employee to supervisor (30 minutes)
  • Daily meetings: Inform and align the team (15 minutes)
With wife Louise and son William Harrington Leahy at Mare Island, California, in October 1905

Then the final step is to publish the new battle rhythm to your team. The team needs to understand the cadence and the purpose of the meetings. In addition, your team will help keep you accountable for making these meetings happen going forward.


As a naval cadet

Interested in having a Leadership Experience that uses history and its leaders to enhance your team’s leadership today? We offer the D-Day, Market-Garden, and Battle of the Bulge Leadership Experiences in Europe and the War in the Pacific Museum and Pearl Harbor Leadership Experiences in the United States. Send me an email and we can start the discussion today about building better leaders in your organization.

In the meantime, go on the offensive and review your battle rhythm.

Written by David Fivecoat

Managing Partner of The Five Coat Consulting Group & Former US Army Paratrooper
World War 2

US Navy Admiral Leahy : “The Second Most Powerful Man In The World”