By now it is something of a truism to say that the terrorist threat is constantly changing and is always adapting to whatever changes it sees itself confronted with. But merely acknowledging the fluid nature of the terrorist threat is not enough. We should, of course, try to understand what those changes entail, if they occur at all, and what they mean for our efforts to fight terrorism. The current ICCT Threat Assessment means to serve as a basis for such discussions. Using data about the numbers, geographical distribution, and modus operandi of terrorist attacks, about returning foreign terrorist fighters and about arrests related to terrorism, the report identifies the most relevant trends and patterns in these areas and gives estimates about what can be read into them. This provides an empirical overview about the current state of the terrorist threat.

This Threat Assessment is a follow-up to the Threat Assessment that ICCT published in 2019 and covers the two-year period between 1 September 2019 and 31 August 2021, unless stated otherwise.