ABSTRACT
This chapter explores interests in hardened borders represented by physical barriers. It employs the approach towards mobility of Van der Velde and Van Naerssen, henceforth called the 'threshold approach'. The chapter argues that barriers without cross-border security cooperation may enable militants to continue attacking despite the barrier and even increase the frequency of their attacks. It employs a single case study as a plausibility probe to determine the theory's validity and applicability. The chapter examines present contributions on border security and barriers, and defines barriers and borders and explains how the threshold approach applies to the interaction between barriers and militants as border crossers. It establishes the relationship between presence or lack of local security cooperation and militant activities and explicates the effect of barriers on the strength and weakness of militant groups' supply institutions. The chapter considers the Gaza barrier case as a preliminary probe of the plausibility.
