War of aggression

A war of aggression is a military conflict started without the justification of self-defense. These wars are often fought for territorial gain or to subjugate other people. This is sometimes called a "war of choice." It differs from a "just war" or a "war of necessity." In a just war, the fighting is seen as necessary or legally sanctioned. An aggressive war lacks this legal or moral standing. It is often viewed as an attempt to take land or power by force.

To understand aggression, one must look at how it is defined by international law. In 1933, two Conventions for the Definition of Aggression were signed in London. These treaties used the "Politis Report" to list specific acts. A declaration of war against another state is one act. An invasion by armed forces is another. Attacks by land, naval, or air forces are also included. A naval blockade of a country's coasts or ports counts as aggression. Finally, supporting armed bands that invade another state is an act of aggression.

History shows how difficult it has been to stop these conflicts. The League of Nations was a group meant to maintain peace. However, it struggled to influence strong nations. For example, the Japanese invasion of Manchuria weakened the League's moral strength. This showed that a strong nation could pursue aggression without serious consequences. Following this example, Benito Mussolini of Italy invaded Ethiopia from 1935 to 1937 and Albania in 1939. Adolf Hitler of Germany invaded Czechoslovakia between 1938 and 1939, and then Poland in 1939.

After World War II, the world created new ways to judge these actions. The International Military Tribunal at Nuremberg held trials for leaders. The tribunal stated that war is essentially an evil thing. They argued that its consequences affect the entire world. Because of this, starting a war of aggression is considered a supreme international crime. This crime differs from other war crimes because of its massive scale. These legal ideas became known as the Nuremberg Principles. They were later used to form the basis of the United Nations Charter.

The United Nations Charter provides a system for managing these issues. Article 39 gives the UN Security Council the power to determine if aggression exists. The Council can then recommend or decide on measures to restore peace. These measures are found in Articles 41 and 42 of the Charter. The International Criminal Court (ICC) also views aggression as a serious crime. For a long time, the ICC could not prosecute this specific crime. This was because the states involved had not agreed on a definition.

Progress was made during the Kampala Review Conference on June 11, 2010. At this meeting, 111 State Parties to the Court reached a consensus. They agreed on a definition of the crime and the conditions for prosecution. These amendments to the Rome Statute entered into force on July 17, 2018. This happened after 35 States Parties ratified the changes. This allowed the ICC to finally exercise jurisdiction over the crime of aggression. This was a major step in international law.

Today, the concept of aggression connects to many different legal systems. Nations that enter armed conflicts must now justify their actions. They must argue they are using the right of self-defense or collective defense. They may also argue they are enforcing the law of "jus cogens." This is a term for fundamental principles of international law. Because of these rules, the formal declaration of war has become uncommon since 1945. The world continues to use these frameworks to try and maintain global security.