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.

We must take all that territory away from ISIS.

The homegrown terrorists are the most significant because any fighter returning from Syria to the United States would likely be identified and detected by our intelligence and law enforcement agencies.

Cyberespionage and cyberattack is exploding from our adversaries inside our country. We don't seem capable of stopping it.

Rebuilding the military is something Putin will pay attention to.

I have lots of concerns at working with Russia going against ISIS until we have agreements in terms of what Russia's behavior is going to be.

Radical Islam, it has grown into a global jihad.

I watched the Bush administration overreact to the Clinton administration, who believed they did too much nation building, sustaining other countries, and that's why we never put the commitment on Afghanistan and Iraq that should have been in there under their policy leadership.

One of the banners I would put up in front of any American president and new administration is 'Do not overreact to your predecessors' policies.'

ISIS itself, it draws its central belief system from the Koran and from the writings of the Prophet Muhammad. That is undeniable. And it's a medieval interpretation of it. It is a literal interpretation of it.

To get an Army that's already fighting a war to change in stride to a total different military strategy on the ground - and to get everybody on the same page - was accomplished by the sheer force of Dave Petraeus' will.

Al Qaeda has overplayed their hand. What the al Qaeda do when they go into a town or village or a neighborhood inside a major city is they get a stranglehold on the people themselves. They force the men to wear beards and the women to be properly costumed and essentially completely covered up.

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. They actually said that in many of their transmissions that we were able to pick up. And the Shia militia, largely those trained by the Iranians in Basra and also in Sadr City, had been defeated.

The issue with Syria, I think for many of us, has always been about Iran. This is an anchor point for them in terms of regional domination. It means a lot to them. They are all in here.

Here's the problem the Free Syrian Army has. They really want to topple the regime in Damascus, and this is where most of the fight takes place, between Aleppo and Damascus for the Free Syrian Army.

Putin has put Russia on a path to be a world power with global influence.

When you had thugs and bullies and killers imposing their will on their own people or other people - if you don't respond to it, it just keeps coming because they're encouraged by their own success.

Frankly, our adversaries are emboldened by the lack of American leadership in the world, and our friends and our allies, they have lost trust in us.

The military executes policy decisions.

Actually if you were to buy a bag of dried lentils it would cost you a couple of quid. Some people don't have that to spend in the first place. And not everyone wants to eat lentils.

Food is a weapon in austerity Britain. Hunger, the threat of and the reality of, is used to coerce and control.

We have an odd culinary relationship with tinned food. In higher society, rare and supposedly exquisite goods such as tinned baby octopus, foie gras and caviar come in beautifully crafted, artistically designed tins.

Food is such a basic need, a fundamental right, and such a simple pleasure.