راهکارهای اشکانیان در مرزداری و برقراری امنیت داخلی

Introduction
The ability to defend the territory is considered one of the necessary conditions for a political unit as a state (Sancisi Weerdenburg, 2009: 291). Any political system must have sufficient authority to defend its borders to become a state. This issue was more important in ancient times because the disorder and the risk of invasion by nomadic and primitive tribes as well as the lack of adherence of rival governments to political agreements in ancient times were greater than today. This research aims to identify the strategic decisions of the Parthians in protecting the borders and establishing security inside the country. The strategies of the Parthians in confronting and preventing the external and internal dangers of their vast territory are examined with a structuralism approach. The main research question focuses on the executive mechanisms of the Parthian state to realize internal and border security. For this research, simultaneous sources and Parthian material culture such as the remaining defensive fortifications are examined. As a result, a general overview of the internal and border forces and fortifications of the Parthian Empire will be obtained, and the analysis of these data can determine the executive mechanisms of the Parthians in achieving internal and border security.

Research Literature
Clarifying some of the Parthian Empire’s state management strategies and problem-solving procedures is crucial for understanding the significance of this research. Other facets of this research, which are significant in interpreting the Parthian historical events, include evaluating how well this state’s intellectual machinery performs in dealing with novel challenges, its capacity to adapt to circumstances, and its ability to manipulate the status quo for its gain.
Border Management in the Parthian Empire
During its long and fluctuating history, the Parthian Empire had to contend with primitive tribes and emerging civilizations in the east, west, and north of its territory. These military conflicts caused the borders of this empire to be constantly changing, and therefore, when talking about the borders of the Parthian Empire, the time in question should be clarified. It can be said that this empire at its peak power during the reign of Mithridates II and Orodes II reached from the east to Herat, and even possibly to Bactria (Olbricht, 2013: 18-19) and the old route of the Amu Darya River (Diakonov, 1972: 57) which flowed into the Caspian Sea and included the territory of the Massagetae (College, 2009: 46).
Security in Cities
The features and requirements of the ancient world required governments to protect the cities as much as possible against common problems in addition to controlling the security within the country. The Parthian state had thought of effective measures in this case. The cities themselves had an independent nature in the Parthian Empire, which made them somewhat self-sufficient in relation to the outside world. During this period, cities usually had two circular or quadrangular plans, the first of which probably originated in Central Asia (Bussagli, 2010: 14-15). Defensive walls protected these cities.

Conclusion
The Parthian Empire managed to grow from a local power in the mid-third century BC to a global power in the mid-second century BC within a hundred years. Thus, it is necessary to examine the executive and administrative mechanisms of this empire to understand the reasons for the success and stability of this government. Every state needs to expand security inside and on the borders of its territory to maintain order and stability as well as military and political progress. The evidence shows that the Parthian statesmen understood this point well and tried to control the internal and border security of their country by taking advantage of the past heritage and to a large extent with effective innovations. The Parthians managed to control the security in the cities by establishing military and law enforcement authorities in the cities, monitoring entry and exit, and exploiting the ideology of the king’s holiness and high status. The construction of military forts inside the country and along important caravan routes was another important step in the development of the country’s internal security, which led to the progress and prosperity of commerce. In addition, the Parthian statesmen tried to establish security and increase surveillance on the edges of their territory by agreeing with primitive and nomadic tribes and moving military prisoners and different tribes to the borders, while following the old patterns of the region. The construction of numerous border forts was also one of the strategies of the Parthian state to deal with foreign invasion, which was successful in many cases. Therefore, in general, the Parthian state should be counted among the successful governments in the matter of security control in Iran. Not only do the simultaneous sources report the relative success of the Parthians in expanding border and internal security, but there are few reports about the large-scale rebellions of local tribes and the civil wars of Iran during the five centuries of the Parthian Empire. This indicates the superiority of Parthian security and defense mechanisms compared to the Roman Empire, as a rival and hostile state.