“In any organization, it’s all about selecting the right team. The two qualities I was taught to value most in selecting others for promotion or critical roles were initiative and aggressiveness.” – James ‘Mad Dog’ Mattis
James Norman Mattis, callsign “CHAOS” (informally referred to as “Mad Dog”), is one of the most prominent American military leaders of the 21st century.
His career spanned four decades, allowing him to serve in a number of positions, from the Marine Corps to the position of Secretary of Defense.
U.S. Marines with 2nd Battalion, 8th Marine Regiment, currently forward deployed with 4th Marine Regiment, 3rd Marine Division as part of the Unit Deployment Program, engage a simulated enemy while rehearsing squad attacks during the Korean Marine Exchange Program 26.1 on Suseong-Ri, Pohang, South Korea, April 2, 2026. The Korean Marine Exchange Program (KMEP) is a semi-annual exercise that provides opportunities for ROK Marine Corps and U.S. Marine Corps units to train together, improving their combined capabilities to deter threats and maintain peace on the Korean Peninsula. (U.S. Marine Corps photo by Cpl. Joaquin Dela Torre)
He was known for his aggressive leadership style, yet he still harbored a strong sense of discipline and restraint.
Early Life and Military Career: James ‘Mad Dog’ Mattis
Mattis was born on September 8, 1950, in Pullman, Washington, and grew up in the Pacific Northwest. His early life was typical for a working-class family.
From a young age, however, he showed an intense interest in reading, history, and military affairs, which would later shape his life. He attended Central Washington University, where he earned a degree in history in 1971.
Mattis developed a strong love of learning in the early half of his life. He treated learning as a lifelong obligation, a view he carried with him throughout his military career.
Commissioned as a second lieutenant in the U.S. Marine Corps in 1972, Mattis entered a profession that he would remain devoted to for more than forty years.
In his early years in the Marine Corps, he was assigned to platoon and company-level commands, as well as staff positions. Over time, he developed a reputation for demanding high standards while also taking personal responsibility for the welfare and preparedness of his Marines. He believed that leadership was both a moral and professional duty, requiring constant self-improvement and accountability.
U.S. Marine Corps Lance Cpl. Elijah Geiwitz fires an M4 carbine in the short bay during a live-fire rifle range for the combat marksmanship course on Camp Hansen, Okinawa, Japan, March 13, 2025. CMC refines Marines marksmanship fundamentals and enhances their lethality through advanced marksmanship training. Geiwitz, a native of Wisconsin, is an automotive maintenance technician with 3rd Landing Support Battalion, 3rd Marine Logistics Group. (U.S. Marine Corps photo by Cpl. Michael Taggart)
Career in Iraq and NATO Command
Mattis gained national and international attention for the first time during the 2003 invasion of Iraq, when he commanded the 1st Marine Division. Under his leadership, the division conducted a rapid and aggressive advance from Kuwait to Baghdad, contributing significantly to the collapse of Saddam Hussein’s regime.
Despite the speed and intensity of the campaign, Mattis remained disciplined and restrained, curtailed by the asymmetrical nature of warfare in the Middle East.
Following the initial phases of the Iraq War, Mattis continued to rise through the highest levels of military command. He led the I Marine Expeditionary Force and later served as Supreme Allied Commander Transformation at NATO, a role focused on preparing alliance forces for future conflicts. In this position, he worked on issues such as joint operations, modernization, and adapting large military institutions to unconventional threats. In 2007, he was promoted to four-star General.
In 2010, Mattis assumed command of U.S. Central Command, placing him in charge of American military operations across a vast and volatile region that included the Middle East and Central Asia.
Replacing General David Petraeus, he took command of CENTCOM when the Global War on Terror was at its peak. During his tenure there, he advised then-President Obama to take a more aggressive stance in the Middle East, particularly towards Iran, especially after an Iranian aircraft attacked an American drone in 2011.
While the Obama administration mistrusted him, he remained in his position until his retirement from the military in 2013.
Time as Secretary of Defense
In 2017, following his retirement from active duty, Mattis was nominated to serve as Secretary of Defense under Trump’s first term as President. His appointment required a special congressional waiver because of the recency of his military service, but it received broad bipartisan support.
As Secretary of Defense, Mattis frequently traveled abroad. He met with other defense ministers worldwide and worked tirelessly to restore confidence in the American Armed Forces.
He also continued to supervise the GWOT, keeping his focus set on the Middle East.
Mattis eventually found himself at odds with President Trump regarding the rapid withdrawal of U.S. forces from Syria without extensive coordination. In December 2018, he resigned as Secretary of Defense.
In his resignation letter, he strongly criticized the President for abandoning regional allies in the Middle East and warned that the U.S. may be playing into the hands of China and Russia.
The resignation drew widespread attention, in part because of its restrained yet unmistakably firm tone. After his resignation, Mattis returned to his post at the Hoover Institution.
Leadership Principles
Throughout his career, Mattis was known as an avid reader and a lover of learning. He became well known for his personal library and his habit of reading widely in history and philosophy. He encouraged everyone who served under him, officers and noncommissioned officers alike, to pick up reading and charged them to expand their minds.
Mattis argued that studying past conflicts was essential for avoiding costly mistakes and understanding the human dimensions of war. He often warned that ignorance of history leads to repeated failures, often paid for in lives and blood.
US Marines. Image Credit: Creative Commons.
Underlying this intellectual approach was a broader leadership philosophy centered on competence and respect for institutions.
Mattis believed that leaders owed their subordinates clarity of purpose and realistic planning, and that moral courage was as important as physical courage.
He also strongly supported the principle of civilian control of the military, viewing it as essential to the health of a constitutional democracy.
Throughout his career, he maintained a strictly nonpartisan public posture, avoiding political commentary while in uniform.
About the Author: Isaac Seitz
Isaac Seitz, a Defense Columnist, graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.
