締約国

1. Origins, structure, and basic meaning

• Structure: 締約国 (ていやくこく) adds state 国 to treaty conclusion 締約 to denote a contracting or signatory state.
• Basic usage: It sends representatives to treaty meetings and implements agreed provisions domestically.

2. Common pitfalls and similar expressions

• Treaty party, not merely attendee
  • 締約国 has formally joined the treaty; presence at a meeting alone does not make a state a contracting party.