section_path: Complex systems
section_name: Complex systems
paragraph_text: Complex systems
  
  Another group of theorists, making use of systems theory, looks at a civilization as a complex system, i.e., a framework by which a group of objects can be analysed that work in concert to produce some result. Civilizations can be seen as networks of cities that emerge from pre-urban cultures and are defined by the economic, political, military, diplomatic, social and cultural interactions among them. Any organization is a complex social system and a civilization is a large organization. Systems theory helps guard against superficial and misleading analogies in the study and description of civilizations.
  
  Systems theorists look at many types of relations between cities, including economic relations, cultural exchanges and political/diplomatic/military relations. These spheres often occur on different scales. For example, trade networks were, until the nineteenth century, much larger than either cultural spheres or political spheres. Extensive trade routes, including the Silk Road through Central Asia and Indian Ocean sea routes linking the Roman Empire, Persian Empire, India and China, were well established 2000 years ago when these civilizations scarcely shared any political, diplomatic, military, or cultural relations. The first evidence of such long-distance trade is in the ancient world. During the Uruk period, Guillermo Algaze has argued that trade relations connected Egypt, Mesopotamia, Iran and Afghanistan. Resin found later in the Royal Cemetery at Ur is suggested was traded northwards from Mozambique.
  
  Many theorists argue that the entire world has already become integrated into a single " world system ", a process known as globalization. Different civilizations and societies all over the globe are economically, politically, and even culturally interdependent in many ways. There is debate over when this integration began, and what sort of integration – cultural, technological, economic, political, or military-diplomatic – is the key indicator in determining the extent of a civilization. David Wilkinson has proposed that economic and military-diplomatic integration of the Mesopotamian and Egyptian civilizations resulted in the creation of what he calls the "Central Civilization" around 1500 BCE. Central Civilization later expanded to include the entire Middle East and Europe, and then expanded to a global scale with European colonization, integrating the Americas, Australia, China and Japan by the nineteenth century. According to Wilkinson, civilizations can be culturally heterogeneous, like the Central Civilization, or homogeneous, like the Japanese civilization. What Huntington calls the "clash of civilizations" might be characterized by Wilkinson as a clash of cultural spheres within a single global civilization. Others point to the Crusading movement as the first step in globalization. The more conventional viewpoint is that networks of societies have expanded and shrunk since ancient times, and that the current globalized economy and culture is a product of recent European colonialism.