For the past two decades, statebuilding has been the object of a growing attention from practitioners and scholars alike. ‘International statebuilding’, as its dominant approach or model guiding the practices of national and international actors, has sparked numerous discussions and debates, mostly around its effectiveness (i.e. if it works) and deficiencies (i.e. why it often fails). Surprisingly, little efforts have been made to investigate what international statebuilding, in the multiple ways it is mobilized by various actors, actually produces on the political dynamics of the ‘fragile’ contexts it is supposed to support and reinforce. Using an instrumentation perspective, this dissertation addresses this gap by exploring the relationship between the micro-dynamics of the uses of international statebuilding instruments and the fragility of contexts. This exploration is articulated around five essays and as many angles to this relationship. Using the case of Hamas, Essay I explores the European Union’s (EU) terrorist labelling policy by questioning the nature and modalities of the enlisting process, its use as foreign policy tool and its consequences on its other agendas, especially its international statebuilding efforts in Palestine. Essay II examines a Belgian good governance incentive mechanism and sheds the light on the tension between the claimed apolitical and objective nature of the instrument and the politicization potential embedded in its design and modalities, naturally leading to a convoluted implementation. Essay III analyses the localization dynamics of transitional justice in Burundi and unveils the nature, diversity and rationale behind transitional justice subversion techniques mobilized by national and international actors, which have produced a triple form of injustice. Essay IV widens this scope in Burundi, developing the argument that the authoritarian trend observed in the 2010-2015 period did not only occur against international statebuilding but also through self-reinforcing ...