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.

I'm not in a position to go back into public service.

We have a sufficient political class, and the military doesn't have to get involved in high national office. The days of doing that, post-Civil War and post-World War II, are gone.

If you're going to maintain true authorities over a subordinate organization, you have to have some control over policy formulation of that organization and also the resources that are applied to it.

Qatar has funded and helped arm ISIS. They also, as we all know, fund Hamas. That's got to stop. And we've got to use our pressure against that country to knock that stuff off.

Economically, ISIS is making money every day on the black market with their oil fields. But they are also putting money in banks. We know where those banks are. We should go after the banks and the facilitators using them.

Air power will not defeat ISIS. It has not been able to deny ISIS freedom of maneuver and the ability to attack at will.

What did we want out of Iraq? We wanted a country that was stable and secure, that elected its own government, that was not going to be a threat to its neighbors and also was capable of protecting and defending itself. That was our objective in Iraq.

Fighting forces, particularly ground forces, have to operate on the basis of unit cohesion.

It's not that I can't be fooled, but I'm not fooled often.

This radical Islam is a religious-based ideology. And you actually have to, when you deal with the ideology, you have to attack it on that basis.

The fact to the matter is, we never developed a comprehensive strategy to deal with radical Islam. And the 9/11 commission said one of the things we must do is develop a global alliance to combat it.

President-elect Trump wants to win them if you're going to be involved in a war. I don't think he wants to be involved in war, but when we are, he wants to win.