同盟

1. Origins, structure, and basic meaning

• Structure: 同盟, read どうめい, means an alliance formed for a shared purpose.
• Basic usage: It is used when cities join forces for tourism or former enemies become allies in a story.
  • 三つの町が観光振興のため同盟を結んだ。

2. Common pitfalls and similar expressions

• Cooperation compared with an alliance
  • 協力 broadly describes working together, while 同盟 focuses on a relationship formed through an agreement to act together.