The classical view of security as relating to nation states and the protection of their territory still lies at the heart of thinking about national and international security. Defence in the sense of national defence is a key task of the nation state and for centuries the sovereignty of states has formed the basis of the international legal order. Today, however, security encompasses more than protecting the state's territory against military aggression by another state, as is illustrated in Fig. 2.1. With globalisation and the emergence of new economic powers, for example, the relationship between economic and military security has become a far more prominent issue. In an interconnected world, flow security-safeguarding global flows of goods and services, infrastructural hubs and systems-is of the utmost importance. In a world of transnational connections, protecting national territory against hostile armies is not enough. Moreover, since the 1980s, and to an even greater extent since the end of the Cold War, there has been a significant increase in concern for human rights and for economic and social development (human security). After all, physical violence is partially explained by the structural violence as a result of disadvantaged social circumstances. National and international security are therefore linked to the security of the society and the individual. The security of the nation state is not a goal in itself, but is for the benefit of the society. Particularly since 11 September 2001, the blurring of the boundaries between internal and external security has also entered the debate about security policy 1 with the realisation that non-state actors such as Al Qaida and Da'esh have come to form part of the landscape of security and insecurity. The sovereignty of states over their