In mathematical terms, it would be impossible for any threat to be infinite in size. In this example, limitlessness should not be taken as a question of absolute scale. Instead, the threat’s limitlessness is implied by its unquantifiable character.
From an essentialist standpoint, the terrorist subject can only be defined by virtue of their participation in the act of terror. With the weapon concealed by the terrorist body, there is – prior to the moment of violence - no way of differentiating between the innocent subject and the terrorist-in-waiting.
As long as demarcation remains impossible, there is no way of measuring the potential threat; a threat which remains limitless and unknowable.