What short-term political decisions directly caused war?

The assassination of Archduke Franz Ferdinand of Austria-Hungary directly led to the outbreak of World War I.

The assassination of Archduke Franz Ferdinand of Austria-Hungary by a Serbian nationalist in June 1914 is a prime example of a short-term political decision that directly caused a war. This event triggered a series of diplomatic manoeuvres and ultimatums, which eventually led to the outbreak of World War I. Austria-Hungary, backed by Germany, issued an ultimatum to Serbia, which Serbia partially rejected. This led Austria-Hungary to declare war on Serbia, setting off a chain reaction of alliances that escalated into a full-scale war.

Another example is the decision of the Japanese government to attack Pearl Harbor in 1941, which directly led to the United States' entry into World War II. The Japanese government, under the leadership of Prime Minister Hideki Tojo, made a short-term political decision to neutralise the US Pacific Fleet as a strategic move to secure Japan's expansion in Asia. This surprise attack led President Franklin D. Roosevelt to ask Congress to declare war on Japan, marking the beginning of the US's involvement in World War II.

In a more recent context, the invasion of Kuwait by Iraq in 1990 directly led to the Gulf War. Iraqi President Saddam Hussein decided to invade Kuwait with the aim of acquiring its vast oil reserves and eliminating its debt to Kuwait. This decision was met with immediate condemnation from the international community, leading to a coalition of nations led by the United States to launch Operation Desert Storm, which resulted in the Gulf War.

These examples illustrate how short-term political decisions can have far-reaching consequences, leading to the outbreak of war. It is important to note that while these decisions were made in the short term, they were often the result of long-standing tensions or conflicts, and their impacts were felt for many years afterwards.