Japan IS playing by the rules. It's not their fault if you and paul Watson don't like what the rules are though. Every country I know makes deals or whatever (what you describe as bribery) to garner support for whatever is their interest at stake in world bodies like the WTO, or even the UN.
So you know full well, as does any Brit who lived through the period, that it was only when the "action" wing of the IRA was stopped that the killing and bloodshed ceased, and the non-violent voices could actually get a compromise deal that brought peace. In whaling, it's Sea Shepherd who are the equivalent of the IRA - taking the law into their own hands unilaterally, and it's hard to see how the Japanese will ever be brought to a deal while those bozos keep attacking them.
Greenpeace on the other hand simply films what is going on, and then tells the world.
I can assure you that embarrassment rather than force is a much more powerful weapon in this fight.