The BBC allow the word 'terror' to be linked to ISIS, some mistake surely!

This BBC article entitled 'Islamic State: Can its savagery be explained?' is not by one of it's ever so politically correct journalists who are ever careful not to offend Islamic terrorists, but by:  

Fawaz A Gerges (who) holds the Emirates Chair in Contemporary Middle Eastern Studies at the London School of Economics and Political Science. He is author of several books, including Journey of the Jihadist: Inside Muslim Militancy.

Here's the opening part of the article:

Islamic State has become synonymous with viciousness - beheadings, crucifixions, stonings, massacres, burying victims alive and religious and ethnic cleansing.

While such savagery might seem senseless to the vast majority of civilised human beings, for IS it is a rational choice. It is a conscious decision to terrorise enemies and impress and co-opt new recruits.

IS adheres to a doctrine of total war without limits and constraints - no such thing, for instance, as arbitration or compromise when it comes to settling disputes with even Sunni Islamist rivals. Unlike its parent organisation, al-Qaeda, IS pays no lip service to theology to justify its crimes.

The violence has its roots in what can be identified as two earlier waves, though the scale and intensity of IS' brutality far exceeds either.

 I wonder if the BBC noticed the word 'terrorise' in the second paragraph.