In 2012, General Dempsey, General Petraeus directed the CIA, Secretary Panetta and Secretary Clinton recommended to the president to robustly arm and train the Syrian moderates. He says no. In 2013, conduct a military strike, same national security team, against the Assad regime because he violated the chemical red line. He says no.

My involvement with Guantanamo began as vice chief of staff.

Afghanistan is where much of the al Qaeda journey began. It is the main site where Osama bin Laden, Mullah Omar and their cohort rose to prominence fighting the Soviets in the 1980s. Afghan territory holds special significance to the group, which is committed to retaking it and re-establishing it as the base of a global movement.

The thing I have in common with Donald Trump is, about a dozen years ago, we got a 'Man of the Year' award in New York City, the Hotel Plaza, from the USO.

I read people; that's one of my strengths. It's not that I can't be fooled, but I'm not fooled often.

In 2005 in Iraq, the constitution was written. A new government was elected. That government was trying to take office in 2006.

In the early 2009, a campaign plan developed by Petraeus and General McChrystal to defeat the Taliban, they required a minimum force of 40,000. President Obama rejected that recommendation and provided 25 percent less. He also decided he would pull the force out in 12 to 15 months.

If we have the intent to use the military only when needed, then that also becomes, then, therefore, a credible deterrent.

Historically, aggression unanswered has led to more aggression.

Senator Clinton is very knowledgeable about national security and is probably going to be strong on defense. I have no doubts whatsoever that if she were president in January '09, she would not act irresponsibly and issue orders to conduct an immediate withdrawal from Iraq, regardless of the consequences, and squander the gains that have been made.

If Assad continues to conduct strikes against the Free Syrian Army at will, it would be very difficult for them to have any success against ISIS.

I'm a New York kid, so when I saw that plane that hit the first building, I suspected it was terrorism - blue sky day.

We should be robustly assisting the Free Syrian Army with equipment and also with training.

While conducting a conventional war in Iraq and Syria, ISIS has staged terrorist attacks on a global scale against the people from the countries who are fighting ISIS.

Russia and China completely disagree with the international order that was established after World War II, and they're trying to take it apart right before our eyes.

The only people that have ever fought ISIS in Syria is not the regime; it is the Free Syrian Army.

I totally disagree with the premise that al Qaeda is on the path to defeat. Quite the contrary, al Qaeda has deliberately decentralized its operations - not because of the relentless attacks we have had on its national leadership in Pakistan, but because its strategic objective is to dominate and control Muslim countries in the region.

Yes, we need a force to continue to train, assist, advise the Iraqi army.

United States and our allied partners need to wake up. ISIS is at war with us and civilization.

Aircraft are always going to be something that terrorists are interested in because you bring down an airliner, you have drawn the world's attention.

There are very few fighters in the ISIS organization in Iraq and Syria coming from the United States; most of them have either come from a region of the Middle East or from Europe.

If you took ISIS' oil, that would not stop them. It's not their only source of revenue. It would be a setback, but it would not stop them.

In 2011, General Alston, four-star commander in Iraq, recommended to the President, a force level of over 20,000. The President rejected it and pulled out all the forces with what is now known as a disastrous consequence in Syria.

The Pentagon is a series of wedges. So you have - the outer wedge has windows on the outside, and then inside of that, it has windows with an alleyway; then there's another wedge with windows outside, windows inside. And we call them the E Ring, the D Ring, the C Ring.

The Taliban has not, in my judgment, in any significant way changed their fundamental goal and objective, which is to take over Afghanistan and return to running that country. It doesn't mean that we shouldn't have negotiation talks with them. I think we should. But we've got to be clear-eyed about it.

ISIS is on the offense, with the ability to attack at will, anyplace, anytime.

The Arab Spring, nobody's in the streets demonstrating for radical Islam; they're in the streets with a window of democracy. They want our political reform, our social justice, and our economic opportunity.

In my own mind, it is profoundly disappointing to see what has occurred in Iraq given the sacrifice of our troops, given our commitment to removing Saddam Hussein and putting in place a fledgling government that would have a chance for a stable, secure Iraq.

I have a close association with Gen. Petraeus... What you get in Dave Petraeus is a very unique officer, a combination of intelligence, extraordinary depth of knowledge and understanding.

Sometimes, our expectations of being all-knowing is somewhat unrealistic. At the end of the day, there are people out there who mean harm to us, are thinking about doing harm to us and motivated to do it, and we don't know what that is.

On a professional side, you've got a tough problem to fix, Geoff Miller's going to do it, and he's always going to do it to very high standards, and he's always going to be on the side of right. He's always talking about 'what right looks like' - just a phrase he would always use.

Despite the obvious intelligence and security failures that contributed to the attack against the U.S. Consulate in Benghazi, the reality is that in one night, an al Qaeda-affiliated group destroyed a diplomatic post, killed a U.S. ambassador and three other Americans, and forced an end to clandestine U.S. activity in the area.

Afghanistan remains an opportunity to deal al Qaeda a vital strategic blow, especially since we have abandoned all operations - including counterterrorism operations - in Iraq.

In Washington, D.C., in 2006, Democrats had long since given up on the war in Iraq in terms of any tangible political support for it. The new factor was the Republicans were beginning to give up as well, and they were truly challenging the strategy and the lack of success.

I believe, for a long time, protracted wars test the will of any democracy, to be sure, and people will underwrite a protracted war if they see some progress. But if they don't see progress, and it appears to be futile and useless, then that political support begins to evaporate rather quickly.

Everybody wants to talk about sectarian conflicts of the war in Iraq, but the fact of the matter is, Sunnis have lived with Shias in harmony more in the confines of Iraq, in that land, than they have been in conflict. That's an historical fact.

I remember speaking to a sheik who came back into the political system in late 2008, laid down his arms. His troops became part of the Sons of Iraq, the so-called Sunni Awakening.

By the end of 2008, clearly the Al Qaeda and Sunni insurgency had been relatively stabilized. And in the Al Qaeda's mind, they were defeated.

Very unusual in an insurgency to have absolutely no political agenda other than to return to power. Most insurgents have a political side to them.

Radical Islamists spread from Western Africa through the Middle East, all the way to South Asia to sub-Indian continent.

The Pentagon is actually a 10-story building, five up and five down.

I have decorated soldiers for heroism before, and it was always such an honor to do it.

Since 1989, we have been deploying on an average of every 18 months.

Only four secretaries of defense served longer than Robert M. Gates. Many others were as dedicated; many sacrificed a great deal. Alone among them all, however, Mr. Gates had the task of turning around two wars that the U.S. was losing.

'Duty' is a refreshingly honest memoir and a moving one. Mr. Gates scrupulously identifies his flaws and mistakes: He waited too long, for example, for the military bureaucracy to fix critical supply issues like the drones needed in Iraq and took three years to replace a dysfunctional command structure in Afghanistan.

Most people who aspire to be president don't have a foreign policy and national security background. The exception was certainly Hillary Clinton.

Russia, their number one client in the Middle East is Syria; that is their foothold in the Middle East. They want to have influence there.

The fact that we walked away from the Middle East, as distasteful as it was for us to stay involved and prevent wars, based on our long involvement there, we have helped to create and provide a foundation. Obviously for ISIS and also for the absolute barbarianism and human catastrophe that Assad impacted on his people.

The success of ISIS is largely tied to the safe haven it has in Syria.

ISIS is at war with America, but America is not at war with ISIS - not the president, nor the Congress, and certainly not the American people.