When it comes to the international system, realists believe that changing distributions of power are dangerous. The territorial boundaries, spheres of influence, and international regimes of the old order may no longer be stable. A rising power may use its newfound military capability to change existing territorial boundaries or even to completely conquer and annex all of the territory of a neighboring state. Extant spheres of influence within which a dominant power is able to influence or dictate the important foreign policy choices of subordinate states, including their security alliances and trade policies, may crumble, if they are challenged by a rising power that can make credible threats with regard to military action and trade sanctions, or offer promises of greater security or prosperity. International regimes, whose rules, norms, principles, and decision-making procedures have been taken for granted or at least not actively challenged, may not be sustainable if a rising power refuses to adhere to them or offers some alternative principles and rules that might be more attractive for weaker states.