Who is Gen. James Mattis? Donald Trump announces pick for defense secretary

U.S. President-elect Donald Trump stands with retired Marine Gen. James Mattis following their meeting at the main clubhouse at Trump National Golf Club in Bedminster, New Jersey, U.S. in November. | Reuters/Mike Segar

U.S. President-elect Donald Trump has so far picked nine out of the 15 cabinet positions that he needs to fill up, and retired Marine Corps Gen. James Mattis was formally announced by Donald Trump as his nomination for the position of Defense Secretary on Tuesday, Dec. 6.

Mattis, who has earned the nickname "Mad Dog," is known in military circles for his toughness and charisma as a combat commander. Back in 2013, the Marine Corps Times dubbed him as "most revered Marine in a generation."

Mattis has over 44 years of distinguished military service under his belt. He was a key figure in U.S. military involvement in the Middle East, particularly in the Iraq war. He led forces in southern Afghanistan and commanded a Marine division as a general during the invasion of Baghdad in 2003. He is credited for leading American and British forces in the bloody Battle of Falluja in Iraq in 2004.

In 2007, Mattis became head of U.S. Joint Forces Command and NATO Supreme Allied Commander Transformation, and in 2010, he was appointed head of Central Command, playing a key role in the U.S. involvement in the conflicts in Iraq, Afghanistan, Syria and Yemen.

The retired general also attracted controversies on several occasions. In 2004, he ordered a bomb assault on a "suspected foreign safe house" in a small Iraqi village; the suspected enemy hideout turned out to be the venue of a wedding. The attack killed around 42 civilians, including children.

In 2005, he came under fire for stating "it's fun to shoot some people" during a panel discussion in San Diego, California. He even added, "Actually it's quite fun to fight them, you know. It's a hell of a hoot."

At Tuesday's rally, both Trump and Mattis pointed out that one obstacle remains in the latter's appointment as head of Pentagon. A law prohibits military officers who have not been retired for at least seven years to assume a cabinet post. Both men are both hopeful that the Republican-dominated Congress will pass a waiver to allow the Mad Dog, who retired only in 2013, to serve as U.S. defense secretary.