<P> Other suggestions have been made that a great power should have the capacity to engage in extra-regional affairs and that a great power ought to be possessed of extra-regional interests, two propositions which are often closely connected . </P> <P> Formal or informal acknowledgment of a nation's great - power status has also been a criterion for being a great power . As political scientist George Modelski notes, "The status of Great power is sometimes confused with the condition of being powerful, The office, as it is known, did in fact evolve from the role played by the great military states in earlier periods...But the Great power system institutionalizes the position of the powerful state in a web of rights and obligations ." </P> <P> This approach restricts analysis to the post-Congress of Vienna epoch; it being there that great powers were first formally recognized . In the absence of such a formal act of recognition it has been suggested that great power status can arise by implication, by judging the nature of a state's relations with other great powers . </P> <P> A further option is to examine a state's willingness to act as a great power . As a nation will seldom declare that it is acting as such, this usually entails a retrospective examination of state conduct . As a result, this is of limited use in establishing the nature of contemporary powers, at least not without the exercise of subjective observation . </P>

Which country became the dominant world power as a result of the napoleonic wars