International student mobility contributes to a knowledge-based economy and forms an important component of a highly educated migration. This paper aims to identify how far political factors--including political discrimination, restrictions, freedom, UK migration policies and social cultural norms and policies--enhance or inhibit individuals' capabilities to become mobile. It offers a novel conceptualisation of mobility, drawing on structuration theory and the capability approach, to reveal the link between structure, capability and agency in the mobility process. Semi-structured in-depth interviews were conducted with 40 PhD students, two professors from Turkey in the United Kingdom and three international education experts. A capability list established shows how mobility occurs when students' capabilities (freedoms) fail to flourish and they lose their power (capacity) to influence society due to the political environment in the home country. 'Impo-mobility', derived from the word 'imposed', is proposed to refer to highly educated people having to become mobile as a result of impositions placed upon them by home and host-government political practices. An appealing political environment is necessary if Turkey is not to lose highly educated individuals and the United Kingdom is to remain a global player in international higher education.