However, what makes Waltz different from Thucydides is the fact that Waltz realizes that this explanation was not adequate. He points out that it is mankind, which creates communities, regimes and other parameters, which defines its existence. As a result, he is of opinion that the second source of conflict is determined by the internal character of the state in which he/ she lives, namely the public beliefs and practices, opinions and expectations, political systems and institutions of government, that frame human behavior.
Waltz does not stop here but goes further. He argues that if the structure of the state and its system of governance shapes human behavior, then the structure of the international system must also shape state behavior. Thus his concept of neorealism shuns essentialist beliefs that human nature does not explain international politics, rather rests in aconstant state of amorphous decentralized latency, which arises from mutual lack of trust and everytime the state develops technological and warfare power, which he calls offensive orovertly aggressive so as to create too much of international felling of insecurity, so much so that they are motivated to seize that power and check it to a normal condition. International politics is different than domestic politics, though, because no entity possesses a legal monopoly on the use of force. The countries of the world inhabit a self-help system, competing freely and independently to secure their own interests and promote their national security. There is no global structure capable of preventing one state from attacking another. This is the third source of conflict--a condition of anarchy that does not make war inevitable, only possible. Waltz argued that states must be prepared to use military force if necessary to protect them. No one else will do it for them. Considering these three sources of conflict, the concept of whether man, the state, or the international system is paramount becomes problematized. Interestingly, Waltz argues that we need to consider all three. Waltz argues that the world exists in a state of perpetual international anarchy. Waltz distinguishes the anarchy of the international environment from the order of the domestic one. In the domestic realm, all actors may appeal to, and be compelled by, a central authority - 'the state' or 'the government' - but in the international realm, no such source of order exists. Hence in Waltz's account, states must behave in a self-help way, acting freely unless or until other actors restrict or limit their ability to do so.
Like most neorealists, Waltz accepts that globalization is posing new challenges to states, but he does not believe states are being replaced, because no other non-state actor can equal the capabilities of the state. Waltz has suggested that globalization is a fad of the 1990s and if anything the role of the state has expanded its functions in response to global transformations. Along with some other theorists, he has argued that the United States has some characteristics of an empire. In 1979 Waltz incorrectly predicted that the Cold War order would continue well into the next century. This wrong prediction, however, does not represent an anomaly in Waltz's theory since it aims to explain continuities rather than change in international system. Waltz's theory, as he explicitly makes clear in "Theory of International Politics", is not a theory of foreign policy and does not attempt to predict or explain specific