A summer-long embargo seems a little extreme, but I can understand why restrictions like these are done. Probably not for an overt political motive, but rather to let one's own country have a more fair opportunity to build its own film industry.
'Fair' is irrelevant, an excuse at best - they will do whatever is advantageous. They didn't roll back protections for any of their other industries, and they won't for this one, either.
What's less understandable are the calls of "We live in a globalized world, that's just how things work now!" when Western nations try the same.