Is there any difference in usage between 参加 and 加盟?

Question

参加{さんか} and 加盟{かめい} are both translated as participation. Are these two words completely interchangeable or is there some nuance in their usage?

Answer 1

「参加」 is an extremely broad term that can refer to participation in any kind of gathering, event, trip, etc. from the very informal to the somewhat formal. It has a nuance of "to join in".

「加盟」 is a more formal word than 「参加」. You do not 加盟する in a takoyaki party at a friend's house or a picnic at the park. You can only 参加する in those.

「加盟」 generally refers to the "official" participation in a business- or politics-related association where all kinds of obligations and benefits can accrue. There is a more serious and long-term commitment implied by 「加盟」.

「参加」 can be used to describe a more non-serious, shorter-term (often one time only) type of participation.

For these reasons, careful speakers would rarely use 「参加」 and 「加盟」 interchangeably.