Expansionism is a policy or ideology where a country seeks to increase its territory or influence. This can occur through various means, such as military conquest, colonization, or diplomatic negotiations. Nations often pursue expansionism to gain resources, enhance security, or assert power on the global stage. Historically, expansionism has been a significant factor in shaping world events. For example, the United States practiced expansionism during the 19th century through the concept of Manifest Destiny, which justified territorial growth across North America. Similarly, European powers expanded their empires through colonization, impacting many regions worldwide.