Officials in the George W. Bush administration later criticized the cruise missile strikes that were ordered by President Bill Clinton in Afghanistan in 1998 as only 'pounding sand.'

The inattention of the Bush administration to the threat from al Qaeda had results. Shortly before 9/11, Bush's attorney general, John Ashcroft, turned down FBI requests for some 400 additional counterterrorism personnel.

Candidate Trump had previously opined that 'Islam hates us' and had called for 'the total and complete shutdown of Muslims entering the United States,' an argument he has since modified and moderated.

A key to McMaster's thinking is his 1997 book, 'Dereliction of Duty: Lyndon Johnson, Robert McNamara, the Joint Chiefs of Staff and the Lies that Led to Vietnam.'

President Obama and a small team of senior national security officials were in the unusual position of acting as al-Awlaki's jury, judges, and de facto executioners.

Trump himself has not laid out a clear agenda on the national security issues that are the most pressing for the United States, from the resurgence of the Taliban in Afghanistan to the deepening Syrian civil war to the fight against ISIS in Iraq and Syria and the flexing of Russian muscles under President Vladimir Putin.

Again and again since 9/11, terror attacks in the West have been carried out by second-generation Muslims who are citizens of the very country they are attacking.

Think of ISIS as a pathogen that preys on weak hosts in the Muslim world. In fact, there is something of a political law: The weaker a Muslim state, the stronger will be the presence of ISIS or like-minded groups.

Between November 23, 2002, and January 11, 2003, al-Qahtani was interrogated for 48 days at Guantanamo more or less continuously, kept awake for much of that time by loud music being blasted when he was falling asleep, doused with water and subjected to cold temperatures, kept naked and forced to perform tricks as if he were a dog.

The reason that attacks by American terrorists who are not jihadist militants are sometimes not called 'terrorism' is, in part, because in the United States, terrorism is a crime which has to be in some way be associated with a 'designated' terrorist group such as ISIS.

One of the themes of 'The Longest War,' my book, which came out before the Arab spring happened, was how al-Qaida and bin Laden was losing the war of ideas in the Muslim world, not because the United States was winning them, but because al-Qaida was simply losing them.

Anne Richard, a senior U.S. State Department official, testified at a Senate Homeland Security Committee hearing in November 2015 that any Syrian refugee trying to get into the United States is scrutinized by officials from the National Counterterrorism Center, FBI, Department of Homeland Security, State Department and Pentagon.

Typically, terrorist attacks produce a rally-around-the flag effect as was the case after 9/11 and the huge outpouring of public support that then-President George W. Bush garnered.

Syrian refugees fleeing to Europe do not go through anything like the rigorous process experienced by those who are coming to the States, and the volume of Syrians fleeing to Europe is orders of magnitude larger than it is to the United States.

European countries simply do not have the ideological framework the United States has in the shape of the 'American dream' that has helped to absorb successfully wave after wave of immigration to the States, including Muslim Americans who are well integrated into American society. There is no analogous French dream or German dream.

In February I secured permission to enter Osama bin Laden's compound in the northern Pakistani city of Abbottabad, where he was killed and where he had lived for the last half-decade of his life; the first, and only, journalist to do so.

Bin Laden comes out of a business background - he studied public administration and economics at university, and he worked for his family company, which was obviously a rather successful enterprise.

I am very suspicious of the notion that somehow bin Laden was a media creation... Bin Laden's actions made him into a big deal. Not the media.

Often it is important to listen to what people aren't saying.

I stepped into the bedroom where he was killed and looked up at the ceiling, where you could still see the patterns of blood that had spurted from bin Laden's head when the bullet fired by a U.S. Navy SEAL tore through the terrorist leader's face.

The centerpiece of the Bush administration's case for going to war in Iraq was Secretary of State Colin Powell's presentation to the U.N. Security Council on February 5, 2003, six weeks before the invasion.

Virulent anti-Semitism is, of course, a staple of militant Islamist ideology.

The reason that Islamist militants can assert that jihad is necessary against the perceived enemies of Islam is that there is sufficient ammunition in the Quran to buttress their beliefs. The same could also, of course, be said for the Old Testament, which is full of scenes of violent death visited on the enemies of God.

Seymour Hersh is one of the giants of investigative journalism.

Hersh's account of the bin Laden raid is a farrago of nonsense that is contravened by a multitude of eyewitness accounts, inconvenient facts, and simple common sense.

I was the only outsider to visit the Abbottabad compound where bin Laden lived before the Pakistani military demolished it.

The fact is, working stiffs with few opportunities and scant education are generally too busy getting by to engage in revolutionary projects to remake society. And history, in fact, shows us that terrorism is generally a bourgeois endeavor.

The diagnosis that poverty, lack of education, or lack of opportunities have much to do with terrorism requires a fundamentally optimistic view of human nature. This diagnosis leads to the prognosis that all we need to do to solve the terrorism problem is to create societies that are less poor, better educated and have more opportunities.

Trump, of course, has been very wrong in the past about important issues such as President Barack Obama's place of birth and Mexican immigrants, but the Republican frontrunner is correct in saying that former Republican President George W. Bush did not keep the country safe during the 9/11 terrorist attacks.

There is no hint that Trump wishes to engage in or to foment violence against the enemies, such as immigrants, he has identified as undermining the American way of life.

Trump's pronounced anti-immigrant stance is reminiscent of both Le Pen in France and Orban in Hungary, although he is far from alone in taking such positions in much of today's Republican Party.

If the party of Lincoln wishes to become the party of intolerance, selecting Trump to be its presidential candidate is a good way forward.

Incompetence is a better explanation than conspiracy in most human activity.

The Japanese scored an important victory at Pearl Harbor, but the attack pulled the United States into World War II, and four years later, Japan was in ruins, utterly defeated.

In the public's mind, Special Forces are often confused with the 'door kickers' of Special Operations Forces - such as SEAL Team 6 and Delta Force - who are the United States' elite counterterrorism operators.

What made al-Awlaki so influential is that, unlike a number of leaders of al Qaeda such as Osama bin Laden, he was a cleric, so he could present himself as a leading religious figure. Second, because al-Awlaki had spent much of his adult life in the States, he communicated with his followers in colloquial, accessible American English.

Islam is, to be sure, a big tent, and the one and a half billion Muslims in the world run the gamut from mystical, moderate, pacific Sufis to Salafists.

The dangers of TATP bombs can be seen in the case of Matthew Rugo and Curtis Jetton, 21-year-old roommates in Texas City, Texas. They didn't have any bomb-making training and were manufacturing explosives in 2006 from concentrated bleach when their concoction blew up, killing Rugo and injuring Jetton.

If the CIA and other U.S. intelligence agencies were private companies and were chronically unable to accomplish one of their key missions, their shareholders would have long ago revolted, fired their management, and their stock would be trading at values near zero.

A decade and a half ago, the U.S. Air Force dropped massive 15,000-pound 'Daisy Cutter' bombs on the Tora Bora complex where Osama bin Laden was hiding in December 2001.

The Russians have been waging wars with these separatists since the 19th century, but for obvious reasons, Chechen separatist terrorism tends to be carried out by Chechens.

Iraqi dictator Saddam Hussein brutally repressed all forms of opposition to his regime, and before the Iraq War, al Qaeda had no presence in Iraq.

I've interviewed multiple people who know bin Laden... who tend to have a universal picture of what he's like, which is: modest, retiring, unassuming, kind of thoughtful - lots of things that don't fit with a mass murderer, which he is as well.

What is tricky for those hoping to utilize such weapons is that TATP bombs are quite difficult to make because their ingredients, when combined, are highly unstable and can explode easily if mishandled.

The Sunni militants that make up ISIS are not the underlying problem in Syria and Iraq, but rather they are a symptom of other deeper problems.

Sheikh Rahman's fatwa was the first time that anyone associated with al Qaeda had given religious sanction to attacks on American aviation, shipping and economic targets.

We climbed the stairs to the third floor, where Osama bin Laden died early in the morning of May 2, 2011.

Bin Laden was 200 miles away from the area where all of these drone strikes were taking out his key leaders, he was able to indulge in his hobbies... and he was making occasional video tapes and audio tapes to the wider world.

And in the end, bin Laden died in a squalid suburban compound surrounded by his wives and children and far from the front lines of his holy war.

ISIS may be a perversion of Islam, but Islamic it is, just as Christian beliefs about the sanctity of the unborn child explain why some Christian fundamentalists attack abortion clinics and doctors.