Transnationalism refers to the phenomenon whereby "certain kinds of relationships have been globally intensified and now take place paradoxically in a planet-spanning yet common – however virtual – arena of activity. It also is often associated with the process of deterritorialization insofar as increasing mobility and the development of communication have intensified transborder relations, leading to social and political mobilizations beyond boundaries and the development of global-scale identities. Stephen Vertovec argues that across the globalization literature, transnationalism refers to a set of variegated transnational phenomena which include communities, capital flows, trade, citizenship, corporations, inter-governmental agencies, non-governmental organizations, politics, services, social movements, social networks, families, migration circuits, identities, public spaces and public cultures."
(Jones, A., Dictionary of Globalization, Cambridge: Polity, 2006, p. 219-220)
The Evolution of the Term
"In the 1960s the word ‘transnational' was widely used to refer to the establishment of corporate structures with established organizational bases in more than one state (Martinalli 1982). In a separate intellectual tradition, several generations of scholars had been using the adjective ‘transnational' to signal an abatement of national boundaries and the development of ideas or political institutions that spanned national borders.
[…]
Transnational processes are increasingly seen as part of a broader phenomenon of globalisation, marked by the demise of the nation-state and the growth of world cities that serve as key nodes of flexible capital accumulation, communication, and control (Knox 1994; Knight and Gap-pert 1989)."
(Glick S., N. and L. Basch, "From Immigrant to Transmigrant: Theorizing Transnational Migration," Anthropological Quarterly, 1995, Vol. 68 Issue 1, pp. 48-63)
The Ascendancy of Sub- and Transnational Spaces and Actors
"The key nexus in this configuration is that the weakening of the exclusive formal authority of states over national territory facilitates the ascendancy of sub- and transnational spaces and actors in politico-civic processes. These are spaces that tended to be confined to the national domain or that have evolved as novel types in the context of globalisation and digitisation. This loss of power at the national level produces the possibility of new forms of power and politics at the sub-national level and at the supra-national level. The national as container of social process and power is cracked (P. Taylor 2000; Sachar 1990)."
(Sassia, S., "Global Cities and Diasporic Networks: Microsites in Global Civil Society" in Global Civil Societies 2002, eds. Helmut Anheier et. al., Oxford University Press, 2002, p. 217)