Why did the roman town require protection in AD 200s?

In the 200s AD, Roman towns required protection due to increasing threats from external invasions, particularly from Germanic tribes and other groups along the empire's borders. Additionally, internal challenges, such as political instability and economic difficulties, heightened the need for security. The Roman Empire was also experiencing a decline in centralized control, making towns more vulnerable to attacks and necessitating fortified structures and military presence for defense.