Further to all those incendiary doctors, the BBC suggests that, if you want to get a jihadist into the United Kingdom, the National Health Service is an easy way to do it:

The NHS has traditionally depended on overseas doctors to help keep the health service running.
The most recent figures show that almost 128,000 of the 277,000 doctors on the GMC register have been trained abroad.
Of these 1,985 are from Iraq and 184 from Jordan.
The skills gap has meant that, with the exception of consultants, doctors did not require a work permit until last year.

That’s one of the lessons from the last few weeks in America: immigration as a societal bonus may be grand and enriching, but a dependence on mass immigration is always a structural weakness, and should be addressed as such.