We often think that globalization has only come into being in the last few decades. This is, however, not the case. Globalization has been going on for centuries. The agents of globalization today are essentially the same as agents of globalization in past centuries. The only real differences are differences of speed and scale.
In this question, you say that agents of globalization include mass culture, trade, migration, and communications. All of these things existed in past centuries. Let us look at a few examples. The United Kingdom was trading with India 300 years ago. There was migration from Germany and Ireland to the United States in the 1840s. The first cable to link North America to Europe by telegraph was completed in 1858. All of these things helped to create globalization.
However, these agents of globalization work faster and on a larger scale today. Instead of communicating by telegraph between stations, we communicate by internet or telephone directly with one another. Instead of having trade or migration that goes by sailing ship, we now use airplanes or much larger and faster ships than in times past. Our mass culture is disseminated across many countries very quickly through movies, TV, and the internet.
From this, we can see that the agents of globalization have not changed over the centuries. They have simply become faster and allowed for globalization on a much larger scale. This has changed the structure of civilizations by making them more similar. In the past, different civilizations could be structured very differently and rulers could keep their societies from interacting with the outside to a much greater degree. Today, this is much less possible, which means that rulers in any given civilization lack the ability to maintain their civilizations’ separation from the rest of the world.