Most Americans had never heard of the Khorasan group until this week, when President Barack Obama announced that U.S. airstrikes in Syria had targeted the "seasoned al-Qaeda operatives." U.S. officials said that the Khorasan group was actively plotting to conduct an attack in the United States or Europe.
Quick: Which U.S. president has authorized wars of various kinds in seven Muslim countries?
On Sunday, ISIS released a new audio recording calling for Muslims to kill Americans and Europeans. In it, an ISIS spokesman states, "If you can kill a disbelieving American or European, especially the spiteful and filthy French, or an Australian, or a Canadian or any other disbeliever, then rely upon Allah, and kill him in any manner or way however it may be."
Over this past weekend, Hezbollah, the militant Shiite group that is headquartered in Lebanon, reportedly used drones to bomb a building used by the al Qaeda affiliated Nusra Front, along Lebanon's border with Syria.
He has beheaded again. The tall, masked British man with the London accent, working with ISIS.
ISIS has Americans worried. Two-thirds of those surveyed in a recent Pew Research poll said they consider the Islamic State in Iraq and Syria to be a "major threat" to this country. But are such fears really justified?
On Thursday in Tampa, U.S. Secretary of Defense Chuck Hagel presided over a change of command ceremony during which Adm. William "Bill" McRaven handed over the reins of Special Operations Command to his successor, Gen. Joseph Votel.
On Wednesday, a propaganda video appeared on the Internet featuring Moner Abu-Salha, the U.S. citizen from Florida who died conducting a suicide bomb attack in Syria for al Qaeda in May.
Douglas McAuthur McCain grew up in the Minneapolis area. Aged 33, he died more than 6,000 miles to the east of his birthplace, fighting in Syria for ISIS, the group that calls itself the "Islamic State."
In a video uploaded to YouTube on Saturday purportedly by the terrorist group ISIS, various scenes of jihadist propaganda flash across the screen: militants reading verses from the Quran and examining a map of northern Syria, clips of violent clashes and explosions.
ISIS demanded 100 million euros ($132.5 million) in ransom for the release of James Foley, the American journalist kidnapped and killed by the terrorist group in Syria, according to a spokesman for GlobalPost, the news website for which Foley freelanced.
U.S. officials are claiming that the terrorist group Islamic State in Iraq and Syria, or ISIS, is "now a credible alternative to al Qaeda."
On Tuesday, an Afghan soldier killed a U.S. major general and wounded a German brigadier general, as well as up to 15 others, in an attack at the Marshal Fahim National Defense University in the Afghan capital, Kabul.
Seconds before he detonated the massive truck bomb that killed him and a number of Syrian soldiers two months ago, Moner Mohammad Abu-Salha radioed other fighters in al Qaeda to say, "I see paradise and I can smell paradise."
ISIS, the brutal insurgent/terrorist group formerly known as al Qaeda in Iraq, has seized much of western and northern Iraq and even threatens towns not far from Baghdad.
On Sunday, Jerad and Amanda Miller, a married couple, allegedly killed two police officers in an ambush at a Las Vegas pizza restaurant and then murdered another person in an adjacent Walmart. During the attack, the couple reportedly stated that their attack was part of a "revolution," according to Second Assistant Sheriff Kevin McMahill.
Following the Taliban prisoner swap that led to the release of U.S. Army Sgt. Bowe Bergdahl, Sen. John McCain, R-Arizona, told Fox News that 30% of the detainees released from the U.S. detention facility at Guantanamo Bay "have already gone back into the fight."
Nearly 13 years after the 9/11 attacks, many Americans were likely surprised to learn that one of their fellow citizens had committed suicide on behalf of al Qaeda in a massive bombing attack last week in northern Syria.
What is the Obama Doctrine? As the President put it Wednesday, "Just because we have the best hammer does not mean that every problem is a nail."
A year ago, President Obama delivered a speech at the National Defense University in Washington in which he made the case that it was time to wind down the "boundless global war on terror " and "perpetual wartime footing" that has been a feature of American life since 9/11.
Drones are everywhere.
Befitting its status as a fast-growing oil exporter, for Nigeria this week was to be a coming out party of sorts, as it hosts the 24th World Economic Forum on Africa. More than a thousand academic, business, civil society and political leaders are supposed to gather in Abuja, Nigeria's capital city, beginning on Wednesday, to discuss "inclusive growth and job creation."
Over the weekend the United States launched drone strikes in two different locations in Yemen, killing at least 15 militants as well as three civilians. At the same time, Yemeni ground forces began what have been termed "unprecedented" operations against al Qaeda's affiliate in Yemen, which may also involve additional U.S. drone strikes, although that isn't clear right now.
On Sunday, a man shot and killed a 14-year-old boy and his grandfather at the Jewish Community Center of Greater Kansas City and then drove to a nearby Jewish retirement community where he shot and killed a third person. Police arrested a suspect, Frazier Glenn Cross, who shouted "Heil Hitler" after he was taken into custody.
One year after the Boston Marathon bombings and almost three years after his death in a CIA drone strike in Yemen, Anwar al-Awlaki, the New Mexico-born American cleric who was an operational leader of al Qaeda in the Arabian Peninsula, continues to be a major influence on violent jihadist extremists in the United States.
A year ago on April 15, two brothers of Chechen heritage who were raised in Cambridge, Massachusetts, were alleged to have carried out a spectacular bombing at the Boston Marathon that killed three, wounded more than 200 and led to a massive manhunt that paralyzed the city and its suburbs for days.
India's general election, the largest democratic exercise in history, begins Monday. Voters will elect 543 members to the lower house of parliament, which will then select the country's next prime minister. Here are 11 things you need to know about the world's biggest election:
Afghans will go to the polls on Saturday to elect their second president since the overthrow of the Taliban in the winter of 2001.
The world's most powerful democracy and the world's most absolute monarchy have long been close, if unlikely, allies.
The Obama administration is proposing to scrap the NSA's bulk collection of all Americans' phone call records.
The New York Times magazine is running a bombshell story alleging that the Pakistanis knew all along that Osama bin Laden was living for years in his longtime hiding place in the northern Pakistan city of Abbottabad, where he was killed by a U.S. Navy SEAL team on May 2, 2011.
Malaysian Prime Minister Najib Razak told reporters over the weekend that "deliberate" action by somebody on board accounted for Malaysia Airlines Flight 370 veering off course.
There is still much that is mysterious about the fate of Malaysia Air Flight 370, but there is emerging consensus that the passenger jet bound for Beijing changed course, flying west over the Indian Ocean and flew for at least four hours. This tends to suggest that there was a human intervention, rather than a mechanical failure.
Sen. Dianne Feinstein is not a bomb thrower.
Nothing gets conspiracy theorists going more than a passenger plane crashing under mysterious circumstances.
Ukrainian security officials are complaining that unknown attackers are interfering with the mobile phone services of members of Ukraine's parliament, making difficult political decisions about what to do about Russia's incursion last week into Crimea that much harder.
"It's tough to make predictions, especially about the future" is an aphorism attributed to the great baseball player Yogi Berra.
The U.S. government's long-stated position is that it won't negotiate with terrorists. But are there exceptions?
President Barack Obama is the first American president known to have authorized the assassination of a US citizen.
When even al Qaeda publicly rejects you because you are too brutal, it's likely a reasonable indicator that you are.
On Friday President Obama will address the nation about the NSA's controversial surveillance programs. He is expected to announce some substantive changes to those programs which collect data about the phone calls of every American.
From around Aleppo in western Syria to small areas of Falluja in central Iraq, al Qaeda now controls territory that stretches more than 400 miles across the heart of the Middle East, according to English and Arab language news accounts as well as accounts on jihadist websites.
The Obama administration has framed its defense of the controversial bulk collection of all American phone records as necessary to prevent a future 9/11.
It has long been said that in war, "truth is the first casualty."
On Sunday's CNN "State of the Union" show, anchor Candy Crowley asked Sen. Dianne Feinstein (D- California), the head of the Senate Intelligence Committee, and her counterpart in the House, Rep. Mike Rogers (R-Michigan), a simple question: "Are we safer now than we were a year ago, two years ago, in general?"
On May 23, President Barack Obama gave a major speech at the National Defense University in Washington stating his intention to recalibrate his counterterrorism strategy, which is now largely defined by a covert CIA drone program that has come under increased public and congressional scrutiny over the past couple of years.
A gruesome snuff video that has garnered more than 180,000 views on YouTube underlines just how grim the Syrian conflict has become.
On the sweltering evening of April 12, 2009, as dusk deepened over the Indian Ocean, several hundred miles off the coast of Somalia, three shots rang out. All the bullets found their targets -- three Somali pirates in a small lifeboat bobbing on the darkening sea.
After the attack on the Westgate mall in Nairobi, Kenya, substantial attention was given to the some 40 Americans who have traveled to fight for Al-Shabaab in Somalia during the past several years.
It was the first major terrorist attack in history in which the group that mounted the operation used Twitter to announce to the world it was responsible.
Of all al Qaeda's affiliated groups, the Somali terrorist organization Al-Shabaab has over the past several years had the deepest links to the United States. Some 15 Americans have died fighting for Al-Shabaab, as many as four of them as suicide bombers in Somalia, and an American citizen even took up a leadership role in the group.
Al-Shabaab, al-Qaeda's brutal Somali affiliate, has claimed credit for the attack by multiple gunmen at an upscale shopping mall in Nairobi, Kenya that has already killed at least 59 people.
Aaron Alexis, the troubled civilian contractor and Navy veteran who killed a dozen fellow workers this week at the Washington Navy Yard, is far from the only veteran or active-duty serviceman to plan or carry out mayhem directed at U.S. military targets during the past decade.
We are about to mark the 12th anniversary of 9/11. Since then, al Qaeda and its affiliated groups haven't launched a successful attack in the United States.
As they contemplate military action against Syria, one of many considerations members of Congress and Obama administration officials have to weigh is how a U.S. strike against the regime of Bashar al-Assad might effect the already complicated, even poisonous, state of Sunni-Shia relations in the region.
Barack Obama came to Washington to end wars. Not to start them.
Why has the Obama administration been so reluctant to intervene in Syria? There are a host of reasons -- American fatigue with war, President Barack Obama's disinclination to start another conflict in the Middle East, and the splintered, fractured opposition to Bashar al-Assad.
What is widely recognized as the most authoritative study of the United States' responses to mass killings around the world -- from the massacres of Armenians by the Turks a century ago, to the Holocaust, to the more recent Serbian atrocities against Bosnian Muslims and the ethnic cleansing of the Tutsis in Rwanda -- concluded that they all shared unfortunate commonalities:
Ayman al-Zawahiri, the Egyptian-born leader of al Qaeda, has seen this movie before: An Islamist party does well at the polling booth only to be overthrown by a military coup that then plunges the country into chaos.
On Friday the U.S. State Department issued a worldwide travel alert because of an unspecified al Qaeda threat. The location of that threat, the department said in a bulletin, is "particularly in the Middle East and North Africa, and possibly occurring in or emanating from the Arabian Peninsula." As a result, an unprecedented 22 embassies and consulates in 17 countries in the Middle East, North Africa and South Asia closed for a day on Sunday.
In an attack orchestrated by a Pakistani Taliban commander, around 250 prisoners, most of them militants, were freed this week at the central prison in Dera Ismail Khan in northwestern Pakistan.
An al Qaeda-produced video posted on a website in early July opens with uplifting images of smiling Syrian children and jovial old men listening to speeches delivered by al Qaeda militants.
The debate over the number of civilian casualties caused by CIA drone strikes in Pakistan is perhaps the most contentious issue in the often fraught U.S.-Pakistan relationship.
On Wednesday, al Qaeda's virulent Yemeni affiliate which is known as al Qaeda in the Arabian Peninsula (AQAP) confirmed the death of the group's deputy leader and co-founder, Saeed al-Shihri, in a video message posted to jihadist websites.
Every July in the lush, green mountains of Aspen, Colorado, many of the top present and former U.S. national security officials and other experts gather to discuss how the war against al Qaeda and its allies is going.
President Barack Obama is seriously contemplating withdrawing all U.S. troops from Afghanistan sometime in 2014, a senior administration official told CNN's Jessica Yellin.
On Monday, Pakistan's long-awaited report into the death of Osama bin Laden in the city of Abbottabad two years ago was leaked in full to Al Jazeera.
The U.S. drone strike that killed Anwar al-Awlaki, an American cleric who was born in New Mexico and who would go on to become an al-Qaeda leader in Yemen, did not silence his siren call to jihad.
Sometime in late 2007, Basaaly Saeed Moalin, a cabdriver living in San Diego, began to have a series of phone conversations with Aden Hashi Ayrow, one of the leaders of Al-Shabaab, a notorious Somali terrorist group.
Testifying before Congress on Wednesday, Gen. Keith Alexander, director of the National Security Agency, asserted that his agency's massive acquisition of U.S. phone data and the contents of overseas Internet traffic that is provided by American tech companies has helped prevent "dozens of terrorist events."
In the most comprehensive speech he has delivered on terrorism, President Barack Obama declared last month that the "core of al Qaeda in Pakistan and Afghanistan is on a path to defeat."
At a hearing on Tuesday, Maj. Nidal Malik Hasan, the Army psychiatrist accused of killing 13 people at Fort Hood, Texas, in 2009, for the first time publicly explained that he was motivated by a desire to protect the leadership of the Taliban -- in particular, Mullah Mohammed Omar, the overall leader of the movement.
In the past few weeks, we've seen a British soldier hacked to death with a meat cleaver on the streets of London and bombers blowing up spectators at the Boston Marathon.
On Thursday, President Barack Obama is scheduled to deliver a major speech in Washington about his administration's counterterrorism policies, focusing on the rationale and legal framework for the controversial CIA drone program and his plans to wind down the prison camp at Guantanamo Bay.
The detainee hunger strike at Guantanamo Bay is entering its third month. Official reports say 100 of the detainees remaining at the detention camp are refusing food; lawyers for the detainees say the number is closer to 130.
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.