One of President-elect Donald Trump's top choices for Secretary of Defense is retired Gen. James Mattis, who is a revered figure among Marines.

What could Americans expect from Mattis if he selected as Defense Secretary? Here are seven things you need to know about the possible Secretary of Defense:

1. Mattis has earned the name of "Mad Dog" because he has a lot of awesome quotes. Here are some of them, per the Washington Free Beacon:

  • "The first time you blow someone away is not an insignificant event. That said, there are some a**holes in the world that just need to be shot."

  • "There is nothing better than getting shot at and missed. It’s really great."

  • "No war is over until the enemy says it’s over. We may think it over, we may declare it over, but in fact, the enemy gets a vote."

  • "You cannot allow any of your people to avoid the brutal facts. If they start living in a dream world, it’s going to be bad."

  • "Demonstrate to the world there is 'No Better Friend, No Worse Enemy' than a U.S. Marine."

  • "I don’t lose any sleep at night over the potential for failure. I cannot even spell the word."

  • "You go into Afghanistan, you got guys who slap women around for five years because they didn’t wear a veil. You know, guys like that ain’t got no manhood left anyway. So it’s a hell of a lot of fun to shoot them. Actually it’s quite fun to fight them, you know. It’s a hell of a hoot. It’s fun to shoot some people. I’ll be right up there with you. I like brawling."

  • "I come in peace. I didn't bring artillery. But I’m pleading with you, with tears in my eyes: If you f*** with me, I'll kill you all." Mattis said this to Iraqi generals.

2. Mattis exudes American values. The Federalist's Rebeccah Heinrichs wrote that Mattis "is humble" and "does not consider himself better than his subordinates or better than the political class that makes modern warfighting so difficult." Heinrichs continued:

My late friend and teacher, Dr. Peter Schramm, after spending an evening with the general, fondly described him and their time this way: “You would not mistake this man for a Roman, or a Russian, or even an English general. An entirely American character, he is disposed to look at things from the inside rather than from without, and certainly not to look down on those of us he is sworn to protect. He understands that in this country all men may rise, that distinction is based only on merit; and he demonstrates gratitude for the opportunity to labor in his field.”

In other words, Mattis is not one of the elitist ruling class that looks down on the rest of Americans, he is a plain-spoken, honest man who can relate to everyday Americans.

3. Mattis had massive success as a Marine general. The Military Times notes that in Afghanistan, "Mattis oversaw the deepest insertion of Marines into a combat zone in U.S. history," prompting Mattis to declare shortly thereafter: "The Marines have landed, and we now own a piece of Afghanistan."

One year later, he went to battle in Iraq:

The following year, Mattis prepared to lead 1st MARDIV into Iraq. In late 2002, he deployed with a staff of fewer than 100 to Kuwait and returned ahead of the March 20, 2003, push over the berm, said Brig. Gen. Paul Kennedy, then a lieutenant colonel working under the general.

Mattis pressed his planners to grasp the intricacies of a massive ground invasion, said Kennedy, now the director of the Division of Public Affairs at Marine Corps headquarters. Artillery, fuel and other requirements all would take up space in convoys that would span miles, Mattis stressed.

Before deploying, division staff conducted numerous rehearsal drills — some using Lego blocks to represent units — to assess challenges it would face. In Kuwait, Mattis had an area bulldozed and turned into a stadium-sized terrain model, said Col. Mike Groen, another lieutenant colonel and planner on Mattis' staff at the time. Rubber tubing served as roads and cinder blocks as cities. Inside, Marine officers navigated the labyrinth wearing jerseys to represent their units.

“He always was a week ahead of everyone else,” said Groen, who is now the director of the Corps' strategic initiatives group and was recently selected for brigadier general. “He would tell you to do something, and you would scratch your head and say, ‘Hmm, I don't really understand why we're doing this.' Three, four, five days later, the light bulb would go off and you would say, ‘Holy smoke, this is what he was talking about!' ”

4. Mattis grasps the true barbarity of radical Islam. At a 2015 congressional hearing, Mattis said, "The fundamental question I believe is, 'Is political Islam in our best interest?' If not, what is our policy to authoritatively support the countervailing forces?"

Some of his other quotes involving radical Islam include, per The Federalist:

  • "Gains achieved at great cost against our enemy in Afghanistan are reversible. We may not want this fight, but the barbarity of an enemy that kills women and children and has refused to break with al-Qaeda needs to be fought."
  • "Having dealt with this enemy since 1979… we are up against an enemy that means what they say and we should not patronize them. When they say ‘girls don’t go to school’ you’re not going to talk them out of it… their views of the role of women, their views of modernity, their views of tolerance for people who think differently are fundamentally different than ours."

5. Mattis has warned about Iran for years...but seems hesitant to rip up the Iran deal. Mattis spoke at a Center for Strategic and International Studies event in April, and called Iran the "the single most enduring threat to stability and peace in the Middle East."

Mattis went on to point out the dangers Iran poses through "nuclear, maritime, ballistic missile, cyber and through its Quds Force," per the Washington Examiner, and while he criticized the Iran deal, Mattis didn't think it would be realistic to tear it up.

"There's no going back," Mattis said. "I don't think that we can take advantage of some new president's — Republican or Democrat — and say we're not going to live up to our word on this agreement. I believe we would be alone if we did, and unilateral economic sanctions from us would not have near the impact of an allied approach."

Mattis went on to say that the U.S. should prepare for war if Iran continues on with their development of a nuclear weapon.

6. President Barack Obama fired Mattis without the common courtesy of a phone call. Mattis, who at the time headed Central Command, was told by an aide through a note in 2013 that Obama was pushing him into retirement early. The reason was because he kept asking "uncomfortable" questions towards Obama's foreign policy team about Iran, such as: "What do you do with Iran once the nuclear issue is resolved and it remains a foe? What do you do if Iran then develops conventional capabilities that could make it hazardous for U.S. Navy ships to operate in the Persian Gulf?" Mattis also clashed with Obama's team on "what to do about mischief Iran is exporting to other countries."

Mattis's common-sense questions were apparently too much for Obama and his team to handle.

7. If nominated, Mattis would need a congressional waiver to serve as Secretary Defense. There is actually a rule stating the Defense Secretary has to be a civilian, and retired military personnel can only serve in the position if they have been retired for seven years. Mattis has been retired for three years.