What is war?

War is an organised conflict usually consisting of intense violence carried out by one state or states against another state or states.

What are the causes of conflict?

The causes of any war are complex. Wars are rarely about just one thing. They can be declared when a state or states act to:

• attack or invade another state, to gain territory or resources
• resist such an attack or invasion by an aggressor
• protect another state from attack by an aggressor
• impose domination or political change on another state, or to resist such domination
• challenge a threat to 'essential national interests' by another state
• counter perceived threats from a different ideology, religion or ethnic group
• defend the national honour when under threat

War can also occur internally within a state between organised groups. This is known as civil war.