Under pressure to explain how the Manchester bomber slipped through the cracks, the UK’s Security Minister described the scope of the jihadist threat facing Britain. From the Australian:

Ben Wallace, the UK Security Minister, told The Times that the existence of a database of 23,000 potential attackers was a stark illustration of the magnitude of the terrorist threat.

“The figures reveal the scale of the challenge from terrorism in the 21st century,” he said. “Never has it been more important to invest in intelligence-led policing.”

MI5’s capacity to investigate is limited to about 3,000 individuals at any one time. People are added to and removed from the group of “live” suspects depending on assessments of who poses the greatest risk.

When an investigation is closed, the people identified drop into a growing group whose risk is seen as reduced. Sources say that the pool of “former subjects of interest” has swollen to 20,000 during the years of Islamist threat since 2001.

Anthony Glees, head of intelligence studies at the University of Buckingham tells the Australian, “To have 23,000 potential killers in our midst is horrifying.” He recommends doubling the size of MI5 to allow them to keep a larger number of jihadists on the front burner.

Others are suggesting even stronger measures. Colonel Richard Kemp suggested on TV this week that it might be time to round up all 3,000 people on MI5’s list and either deport them or put them in internment camps until they can be cleared.

Security Minister Ben Wallace responded to that suggestion the next day saying such a move would set counter-terrorism efforts back because communities most likely to aid the police will stop talking:

This is, of course, a version of the same debate we’ve had here in the U.S. over whether tougher talk about radical Islamic terrorists is “what ISIS wants.” Generally, the left argues that a crackdown empowers the extremists by convincing moderates that society at large sees them as the enemy.

Internment camps are not a good idea but neither is the “keep calm and carry on” mantra promoted by some. It suggests that people are at the mercy of the extremists and that their leaders are willing to tolerate a few (or maybe a few dozen) violent deaths every year in order to avoid hurting people’s feelings.

There has to be a middle-ground in the response somewhere between internment camps and carrying on as if we’re not terrorized by young girls being murdered at a pop concert. The status quo, where MI5 can’t keep track of all the potential terrorist threats, isn’t good enough.