Collective security meant countries acting together to stop aggression. The League could succeed only if governments carried out their promises.
The League of Nations began work in 1920. Its founding agreement, the Covenant, set out ways to avoid war. Countries could discuss disputes or ask an impartial body to judge them, a process called arbitration. Members promised to respect each other's territory and independence.
A state that went to war in breach of the rules could face economic sanctions: other countries cutting trade and financial links with it. The Council could also recommend that governments provide military forces. This was collective security: members were meant to act together against aggression, so an attacker would face more than its immediate victim.
The League had no permanent army of its own. It depended on governments to provide forces and enforce sanctions. Many decisions required unanimity, meaning agreement from all the members involved, although there were exceptions. Britain and France were important members, but acting against an aggressor could conflict with their own financial or security interests.
The United States never joined, so the League lacked the full backing of a major power. Germany was initially excluded but joined in 1926. Membership and rules affected what the League could do; governments still had to choose to cooperate.
Worked example: Why a sanction needs cooperation
Suppose members agree to stop selling essential goods to an aggressor, but other suppliers keep trading.
- The policy aims to raise the economic cost of aggression.
- Alternative suppliers reduce that cost, making the threat less effective.
- To decide whether sanctions worked, check who actually stopped trading and whether the aggressor changed its actions.
Watch out for this
The League could automatically send its own army whenever a country attacked.
It relied on members to contribute force and accept the costs of action. Read the Covenant as a plan, then check what states actually did.
Check your understanding
Which evidence best tests whether collective security worked?
- A rule in the Covenant says members should cooperate.
- Member governments acted together and the aggressor withdrew.
- A state used the word peace in a speech.