A military invasion occurs when one country's armed forces enter another country with the intent to occupy or control it. This action is often driven by political, territorial, or economic motives. Invasions can lead to significant conflict and may result in war, as the invaded nation typically resists the foreign presence. Invasions can involve various military strategies and tactics, including ground troops, air strikes, and naval operations. Historical examples include the D-Day invasion during World War II and the Iraq invasion in 2003. The consequences of military invasions can be profound, affecting both the invaded nation and the aggressor.