On Monday, a U.N. official said that Syrian rebels had likely used the nerve agent sarin.
Killing the man proved easier than killing his ideology.
In her classic 1962 study, "Pearl Harbor: Warning and Decision," Roberta Wohlstetter shows how the Japanese surprise attack on the U.S. naval base on December 7, 1941, should have been less surprising than it appeared at the time because there were warning signs known to the U.S. government that such an attack was possible.
The news that Canadian law enforcement on Monday arrested two men accused of planning to derail a passenger train in the Toronto area has attracted much attention, in part, because the plotters are also charged with "receiving support from al Qaeda elements in Iran."
We don't yet know how or why the Tsarnaev brothers, the alleged Boston Marathon bombers, decided to carry out their attacks, but a look at how their stories correlate with those of some other terrorists living in the West could provide some answers to the questions that many are now asking about them.
In the years since the terrorist attacks of 9/11, eight people have been arrested in the United States for attempting to make the deadly poison ricin with the intent of using it for an act of politically motivated violence, according to terrorism data collected by the New America Foundation.
It's too early to tell who is responsible for Monday's bombings in Boston. Yet after an incident like this, everyone is looking to find out who did it and why.
On Tuesday, al Qaeda's affiliate in Iraq announced that it had merged with the Syrian opposition group Jabhat al-Nusra to form the "Islamic State of Iraq and the Levant."
On the evening of March 19, Tom Clements, the director of Colorado's prison system, was shot and killed when he answered the door of his home near Colorado Springs.
The appearance Friday in a lower Manhattan courtroom of Sulaiman Abu Ghaith, Osama bin Laden's son-in-law and one-time al Qaeda spokesman, to face charges of conspiracy to kill Americans underlines the perhaps surprising fact that members of bin Laden's inner circle have been living in Iran for the past decade or so.
George Venizelos, the FBI's assistant director in charge, asserted Thursday in a written statement that the recently arrested "Sulaiman Abu Ghaith held a key position in al Qaeda, comparable to a consigliere in a mob family."
On Monday Esquire magazine published a massive profile of the Navy SEAL who says he shot Osama bin Laden.
When Vice President Joe Biden and Defense Secretary Robert Gates advised President Barack Obama in late April 2011 that sending a Navy SEAL team into Pakistan to capture or kill Osama bin Laden was not worth the various risks that this operation entailed, John Brennan, the president's top counterterrorism adviser, urged the president to authorize the raid.
The attack in January on a gas facility in Algeria by an al Qaeda-linked group that resulted in at least 37 dead hostages has sparked an outpouring of dire warnings from leading Western politicians.
Afghan President Hamid Karzai will meet with President Barack Obama on Friday to discuss the post-2014 American presence in Afghanistan.
President Barack Obama has nominated his top counterterrorism adviser, John Brennan, to be the next director of the CIA.
On Wednesday, three senior U.S. senators sent Michael Lynton, the CEO of Sony Pictures, a letter about "Zero Dark Thirty," the much-discussed new movie about the hunt for Osama bin Laden, which described the film as "grossly inaccurate and misleading."
The proliferation of semiautomatic weapons in the hands of Americans of the types that were used in the Newtown massacre is sometimes framed as a public health issue in the United States.
The star of the new film "Zero Dark Thirty" is a flame-haired female CIA analyst Maya (played by Jessica Chastain) who is obsessed with finding Osama bin Laden.
"Zero Dark Thirty" is a likely shoo-in, deservedly, for Oscar nominations for best director (Kathryn Bigelow) and best screenplay (Mark Boal) and perhaps a slew of other categories.
Ambassador to the United Nations Susan Rice, a possible nominee to be the next secretary of state, came to Capitol Hill Tuesday to perform a private mea culpa to key Republican senators for her erroneous initial public statements about the perpetrators of the attack on the U.S. consulate in Benghazi in September in which four Americans were killed.
In choosing a new CIA director to replace David Petraeus, President Barack Obama has a range of well-qualified candidates to choose from, although some of the most qualified were in management roles at the CIA when controversial interrogation techniques were used by agency interrogators questioning al Qaeda prisoners and the CIA was maintaining secret prisons overseas to detain members of al Qaeda.
Historians will likely judge David Petraeus to be the most effective American military commander since Eisenhower.
The man charged Wednesday with attempting to blow up the Federal Reserve Bank of New York, the latest alleged jihadist to be charged in a law enforcement sting, may or may not have had the capability to create a major terrorist incident. But if his case follows the pattern of other similar sting operations, what is clear is that he faces very long odds in court.
On Monday, Mitt Romney delivered what his campaign billed as a major foreign policy address, in which he sought to distinguish himself from the man he called the "lead from behind" president.
A decade ago, the United States had a virtual monopoly on drones.
On November 2, 2004, Dutch filmmaker Theo van Gogh was bicycling to work in Amsterdam when he was shot eight times at close range. He died instantly, but in a fit of rage, his assailant, Dutch-Moroccan Mohammed Bouyeri, also attempted to cut off his head with a machete.
On August 15, Floyd Lee Corkins allegedly walked into the Family Research Council in Washington, a conservative think tank, and shot the building manager Leo Johnson in the arm, saying something along the lines of, "I don't like your politics," as he did so.
Covert drone strikes are one of President Obama's key national security policies. He has already authorized 283 strikes in Pakistan, six times more than the number during President George W. Bush's eight years in office.
On Wednesday some media outlets, including CNN, obtained copies of the heavily embargoed book "No Easy Day" by Mark Owen, the pseudonym of one of the Navy SEALs who was part of the mission that killed Osama bin Laden.
A group of former U.S. military and intelligence officers, including retired Navy SEALs, appear in a 22-minute documentary that was released on Wednesday asserting that the Obama administration has leaked considerable classified intelligence about the raid that killed Osama bin Laden for political gain.
Before dawn on Friday, a man wearing an Afghan uniform shot and killed three U.S. soldiers during a meeting to discuss local security issues in the southern province of Helmand.
The word "terrorism" in the United States usually brings to mind plots linked in some way to al Qaeda, while the danger posed to the public by white supremacists, anti-abortion extremists and other right-wing militants is often overlooked.
Pakistan can't get no respect.
On Sunday a missile launched from a U.S. drone struck a house in Pakistan's remote tribal agency of North Waziristan, killing eight suspected militants, most of whom were loyal to the Pakistani Taliban commander, Hafiz Gul Bahadur. Bahadur has reportedly overseen multiple attacks against NATO troops in Afghanistan.
On Monday, Republican presidential candidate Mitt Romney called for the appointment of a special prosecutor to investigate a series of recent leaks that critics charge are designed to bolster the national security credentials of the Obama administration.
President Obama is celebrated and criticized for greatly accelerating the number of CIA drone attacks in Pakistan, but the similar covert war that he has launched in Yemen has received considerably less attention.
The news that Abu Yahya al-Libi, the No.2 leader of al Qaeda, is now confirmed to have been killed in a CIA drone strike in Pakistan's tribal region along the border with Afghanistan further underlines that the terrorist group that launched the 9/11 attacks is now more or less out of business.
It's the diplomatic equivalent of hosting both the World Cup and the World Series in the same country on the same weekend.
At a campaign event Monday in New Hampshire, Republican presidential candidate Mitt Romney asserted that he too would have made the decision to send a U.S. Navy SEAL team to kill Osama bin Laden in Abbottabad, Pakistan, telling reporters, "Of course, even Jimmy Carter would have given that order."
We climbed the stairs to the third floor, where Osama bin Laden died early in the morning of May 2, 2011. 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.
There is no better way for historians to assess Osama bin Laden's thinking and the real state of al Qaeda as it was understood by its leaders in the years after 9/11 than the "treasure trove" of more than 6,000 documents that were recovered by the U.S. Navy SEALs who raided bin Laden's compound in Abbottabad, Pakistan, a year ago.
Nearly one out of every five NATO soldiers killed in Afghanistan this year were killed by Afghan police or army forces. Nine of the 16 victims were U.S. soldiers.
Tapping away at his computer in the study of the suburban compound in Abbottabad, Pakistan, that he called home for the last years of his life, Osama bin Laden wrote memos urging his followers to continue to try to attack the United States, suggesting, for instance, they mount assassination attempts against President Obama and Gen. David Petraeus.
On Wednesday, the Senate and House homeland security committees held their first-ever joint hearing, on the 70th anniversary of the bombing of Pearl Harbor, to address what has become a familiar theme for both committees -- the threat from "homegrown" terrorists.
Pakistani-American businessman Mansoor Ijaz has set off a political firestorm in Pakistan with his claims that he was brokering an offer from Pakistan's civilian leaders to the Pentagon to unseat the leadership of the Pakistani military.
Pakistan, and Pakistani-American relations, confront their worst crises in recent memory.
Recently, both The Washington Post and the German magazine Der Spiegel have reported on meetings between U.S. officials and representatives of the Taliban that have taken place in Germany to discuss some form of peace negotiations.
In late February I posted a piece on CNN.com titled "Al Qaeda the loser in Arab revolutions" making the point that Osama bin Laden must be watching the events in the Middle East unfold with a mixture of glee and despair.
A critique of the U.S. involvement in the military intervention in Libya that will no doubt be common in coming days is that the Obama administration is making a large error by embarking on a war with a third Muslim country, as if reversing Moammar Gadhafi's momentum against the rebels will be a rerun of the debacle of the war against Saddam Hussein.
Osama bin Laden must be sitting in his comfortably appointed hideaway somewhere in northwest Pakistan watching the events in the Middle East unfold with a mixture of glee and despair.
American taxpayers have forked over around half a trillion dollars to U.S. intelligence services since the 9/11 attacks, yet nearly a decade after al Qaeda assaults on New York and Washington, the American intelligence community still cannot answer the most basic of questions:
On May 1, 2003, aboard the USS Abraham Lincoln, President George W. Bush announced "major combat operations" in Iraq had ended. The defeat of Saddam Hussein, he told the American people, was "a crucial advance in the campaign against terror."
He is arguably the most well-known American general since MacArthur, and perhaps the most effective since Eisenhower.
Last week the U.N.'s senior official for extrajudicial executions, Philip Alston, argued in a critical report and remarks delivered in Geneva, Switzerland, that the United States should explain the legal rationale for the CIA's campaign of drone strikes in northwest Pakistan, which he characterized as "a vaguely defined license to kill" that has created "a major accountability vacuum."
Eight years after September 11, the "war on terror" has gone the way of the dodo. And President Obama talks instead about a war against al Qaeda and its allies.
Former Vice President Dick Cheney said in an interview Friday that just-released CIA documents demonstrate the effectiveness of coercive interrogation techniques.
CNN's Barbara Starr reported last week that Gen. Stanley McChrystal, the top U.S. commander in Afghanistan, is expected to ask the Obama administration for additional troops and equipment for conducting intelligence, surveillance and reconnaissance, as well as more military resources to deal with roadside bombs and explosives.
As President Obama awaits formal recommendations this month on issues surrounding the U.S. military prison at Guantanamo Bay, Cuba, it is crucial that policymakers and the public have an accurate picture of the threat to the United States posed by those detainees already released.
Afghan President Hamid Karzai travels to Washington this week to meet with President Obama and with his Pakistani counterpart Asif Zardari.
In the past few weeks as the Pakistani Taliban have marched ever closer to the capital, Islamabad, Secretary of State Hillary Clinton has sounded the alarm about the threat posed by the militants, who she said in congressional testimony pose "a mortal threat to the security and safety of our country and the world."
The Obama plan for Afghanistan and Pakistan announced Friday has a great deal to recommend it, with its emphasis on protecting the Afghan population and delivering more aid directly to the Pakistani people instead of to the Pakistan army.
It is a longstanding cliché that there is no military solution in Afghanistan, only a political one.