Since June, the Islamic State has generated a great deal of publicity and a lot of concern among people who fear the group will attempt an attack in the United States or Europe.
As we have stated previously, we do believe that the fear of militants returning from Syria to stage attacks in the United States or Europe is a valid concern. However, the Islamic State poses only a limited threat to U.S. and European citizens. Now that the Islamic State has replaced al Qaeda as the world's most feared terrorist group, that reality has not changed. One important reason for this is that while the Islamic State does have a great deal of experience conducting insurgent — and now regular — warfare and has conducted terrorism in its region of operations, it has not demonstrated the ability to project sophisticated terrorist capability transnationally.
Nevertheless, there has been much talk among pundits and in social media about the possibility of jihadist groups such as the Islamic State establishing so-called sleeper cells inside the United States or Europe. However, the people making such statements simply do not understand what a sleeper cell really is — or if they do understand, they are being careless in describing them. Perhaps it is not surprising that reporters and academics have misused the term, but some senior government officials are also guilty of misuse.
The issue here is not one of mere semantics: The misuse of the phrase "sleeper cell" blurs important distinctions and contributes to general confusion about the nature of the jihadist threat the United States is fighting. Precise language is needed for clear analysis and more effective defense and counterterrorism efforts.
Defining a 'Sleeper'
In the terminology of espionage, a “sleeper” is an operative who infiltrates the society, or even the government, of a targeted country and is there to remain dormant until activated by a prearranged signal or a certain chain of events.
Sleeper cells were employed during the Cold War. In that context, a sleeper was typically an officer working with a foreign intelligence service. Avoiding detection by counterintelligence and security forces required maximum care when infiltrating a target country. The operative was tasked with carrying out acts of sabotage or gathering intelligence in the case that war broke out. But until activation, a sleeper agent's job was to do nothing operational besides blend into society.
A sleeper differs from what the Soviets (and now the Russians) referred to as an illegal, or what the CIA calls an NOC (officer under non-official cover), because a sleeper is not to undertake operational activity but must remain dormant until activated.
There are great dangers in submerging a sleeper operative for long periods in a target society, so intelligence agencies are very particular about what kinds of people are selected for such assignments. Such operatives must be mentally prepared for the stress they will endure in infiltrating the country and be capable of enduring the monotony of being in place for years without engaging in operational acts or betraying their true identity or purpose. There is also a concern about the sleeper agent going native and developing loyalties to the target country. Only highly disciplined people qualify for such assignments.
Moreover, extensive training in operational tradecraft is needed. Any contact between the operative and deploying government is extremely risky, so a highly sophisticated command-and-control system is needed for communication. This requirement would be multiplied in the case of a sleeper cell, given the need to avoid rousing suspicions or linking members of a cell together.
In short, an operation involving a sleeper must be — by definition — a long-term, strategic project that may take years or even decades to reach fruition. Great vision, sophisticated planning and deep reservoirs of patience are required of the government or group that prepares and deploys such agents, which are assets to be held in reserve until a time of great need.
Covert Jihadist Operatives
Considering this definition, we are not aware of any jihadist organization — including al Qaeda and the Islamic State — that has ever created and run a true sleeper operation or cell. Perhaps the most significant reason for this is that an organization with limited resources would find it difficult to afford an operative, or cell of operatives, who sits in place and does nothing.
As the 9/11 attacks and other past operations have made clear, al Qaeda and other jihadist groups certainly have used clandestine operatives. It is important to note, however, that simply because an operative is hidden does not mean he is a sleeper.
Consider the 9/11 operatives as an example. The men were divided into two groups, the pilots and those who could be termed the muscle hijackers. While the al Qaeda pilots took control of the cockpit, the muscle hijackers wielded the box cutters. Some in the media have equated the pilots with sleeper operatives because they began to arrive in the United States in early 2000, long before their planned attack. But this is a misnomer. After arriving in the United States, these men quickly engaged in operational activities such as attending English classes and enrolling in flight schools. It is clear the 9/11 pilots were sent to the United States with a mission, which they began pursuing almost immediately after arriving.
One of the key aspects to consider in any discussion on al Qaeda and other jihadist groups — and one that is often overlooked — is that these jihadists are non-state actors. Not only do they have to recruit and train personnel to carry out attacks, but they also must set up nodes dedicated to fundraising and logistics. Jihadist recruitment, finance and logistics cells have operated in the United States and Europe for decades now. Examples of such nodes can be clearly seen in a historical review of al Qaeda's activities, and at times these can confuse the sleeper cell discourse.
In the mid-1990s, al Qaeda established a node in East Africa that was headquartered in Nairobi, Kenya. It opened a fake charity called Help Africa People, as well as a gem-trading business, a fishing business and a branch of Osama bin Laden's Taba Investment Company. Alongside these non-terrorist activities, the Nairobi cell was busy with operational planning and was surveilling the U.S. Embassy in Nairobi as early as 1993. The group's planning activities — and its connection to al Qaeda — attracted so much attention that in August 1997 Kenyan and U.S. authorities visited the home of cell leader Wadih El-Hage, seized his computer and other evidence and strongly suggested that he leave the country. Thus, even though the East Africa cell was present and active for several years before the 1998 attacks on the U.S. embassies in Nairobi and Dar es Salaam, Tanzania, it could not correctly be categorized as a sleeper cell given its open relationship with al Qaeda and recruiting and fundraising operations.
Grassroots Groups and Sleepers
Since 1979, tens of thousands of Muslim men have waged jihad in Afghanistan, Bosnia, Chechnya and, most recently, Somalia, Iraq, Yemen and Syria. These men have left their home countries or place of residence to be ideologically indoctrinated and attend training camps in places like Pakistan, Afghanistan and Iraq. During the jihad in Afghanistan and Bosnia, many of these men were recruited by Muslim "charities" associated with the Maktab al-Khidmat, or MAK — known in English as the Afghan Services Bureau — and many even had their travel expenses paid in whole or in part by these charities. These men eventually returned to their home countries but retained their paramilitary skills, their radical mindsets and their relationships with the men they had fought and trained with.
Al Qaeda and other jihadist groups have used such networks to their advantage. When Abdel Basit, perhaps more widely known as Ramzi Yousef, arrived in the United States in September 1992, he was able to use contacts at Brooklyn's Alkifah Refugee Center — one of the U.S. branches of the MAK — to quickly cobble together a team that helped him plan and execute the 1993 World Trade Center bombing. In that case, Basit was not a sleeper because he came to the United States with a mission in mind and quickly got to work on it. The others arrested in connection with that case also do not fit the definition of sleeper operatives. Though they were living in the United States and were, to some degree, embedded in society, they were not deployed by al Qaeda for that purpose. Rather, they came to the country of their own accord before becoming connected to the group. The 1993 World Trade Center attackers were what we refer to as "grassroots" operatives who were organized by an operational commander, Abdel Basit, who was dispatched to the United States from Afghanistan.
Terrorist operations conducted by grassroots jihadists have been far more common in the United States and Europe than the 9/11 model, in which all the operatives were sent into the United States from overseas. We believe that the largest threat to the United States continues to stem from grassroots operatives or lone wolf-type attacks. Grassroots cells lack the strategic reach and punch demonstrated by the 9/11 cell, but they will continue to pose a tactical threat in their areas of operation for the foreseeable future.
Again, it is critical to distinguish between grassroots militants or supporters of jihadist causes and sleeper operatives. If al Qaeda, the Islamic State or any other transnational organization were to demonstrate the strategic vision, reach and tradecraft capabilities necessary for deploying true sleepers, there would be far-reaching implications for the war against terrorism — ranging from counterintelligence policy all the way down to how immigration laws are written and enforced. However, because of the sophistication and expertise they require, there are currently no sleeper cells being operated by jihadists in the West. Though the media will continue to hype the danger of jihadist sleeper cells, in reality, they do not pose any threat to the United States or Europe.