When Tashfeen Malik applied in 2014 for a visa to join her would-be husband in the US she was asked the standard: "Do you seek to engage in terrorist activities while in the United States or have you ever engaged in terrorist activities?" She said "No" – and it is difficult to imagine anyone saying any different.
Malik in December killed 14 innocent people in San Bernardino. Security screening, presumably, went beyond that question and, absurd as it might seem, the authorities might be faulted had they not asked it. But its absurdity underlines the challenge of trying to filter out individual militants from the millions seeking anything from holiday visas to permanent migrant status.
The price of international travel in this age is going to be an inevitably imperfect screening and filtering of travellers, an inevitable trickle of militants into our countries and more attacks. Trump-like prohibitions and walls are impractical, can be circumvented and are deeply divisive.
The challenge of internal screening, particularly for lone-wolf type threats, is yet more difficult. Both the most recent jihadi killers Omar Mateen in Orlando and Larossi Abballa in Paris were well-known to the security services, had been vetted and watched for periods – Abballa had served two years for having terror links. Mateen was investigated twice, once after complaints from workmates that he had boasted of Al Qaeda links. Both were believed not to be a real threat.
Tens of thousands of counterterrorism tips flow to the FBI each year which at any time has up to 10,000 terrorism investigations open. Right now the FBI is investigating 1,000 potential “homegrown violent extremists”, the majority of whom are most likely tied to or inspired by the Islamic State. Fifty to 100 are considered high-priority. Some tips are legitimate.
Others come from vengeful ex-spouses or people casting suspicion on Arab-Americans. Sifting this vast amount of information is almost an impossible task.
In testimony before the French Parliament, the head of domestic intelligence said that about 2,000 French citizens or residents were of concern to the security forces. Some 244 have returned to France from Syria or Iraq, and the intelligence services say they have identified an additional 818 people they believe want to join extremists. The authorities have repeatedly said that it was impossible to monitor them all at all times.
As former FBI agent Erroll Southers observes, the difficulty is trying to identify people who would do things like Mateen. “There is no profile.” In the aftermath of 9/11 the FBI could use Al Qaeda’s hierarchy against the group to intercept communications and identify and track key figures. Today Islamic State encourages anyone to take up the cause and kill in its name. There are no established links or communication trails. Needles in a haystack.