Heywood notes that a great power is “deemed to rank amongst the most powerful in a hierarchical state-system” and identifies four criteria for being a member of this so-called “great power club”:

• “Great powers are in the first rank of military prowess, having the capacity to maintain their own security and, potentially, to influence other powers.

• They are economically powerful states; although (as Japan shows) this is a necessary but not a sufficient condition for great power status.

• They have global, and not merely regional, spheres of interests.

• They adopt a ‘forward’ foreign policy and have actual, and not merely potential, impact on international affairs”