There is a clause that you can kill whales for scientific purposes.   But its obviously not scientific if Japan plans to kill 1,000 whales, they are just saying that so they can kill them.  I'd believe them if they said they were killing 5 whales for scientific research, but 1,000 is ridiculous.

I plan to do some scientific research on eagles.  I'm going to kill 1,000 of them and see how the economy dictates their meat is worth per pound.  I'm also going to see if eagles can take a 1,000 kill hit.

Yeah, the entire world knows that Japan is lying about using the whales for research. They are just exploiting a legal loophole.

Japan really aren't in any position to throw their weight around, but they are fiercely protective of the whaling industry. They will soon bow to international pressure and release the hostages though.