Building a small carrier is the easy part. Learning to operate one effectively is really hard. So far, only the US has really done that. The UK threw away years of experience and has to re-learn again when they get their operating. The Indians, Russians and Chinese are still on the steep part of the learning curve. All the other nations that had operated carriers in the past - Spain, Brazil, Argentina, Thailand - just played with them for prestige.
I say let them build one, they'll learn in time to be a credible threat, they'll have to spend an awful lot of money they don't have at this time to really learn how to use it properly.
BTW...it won't be a 120000 ton monster carrier carrying 100 planes, it will be probably a 20,000 to 30,000 ton small carrier carrying max 20-30 planes.