Japan has said that part of their response to any nuclear activity would be to make their own nukes.
I don't think we should stand in their way.
http://www.freerepublic.com/focus/f-news/1716395/posts
North Korea Nukes Clinton Legacy
Charles R. Smith
Wednesday, Jan. 8, 2003
Asian Arms Race Result of Appeasement Policy
The leftist media spin is that the current crisis in North Asia is the result of George W. Bush calling Pyongyang a member of the 'axis of evil.' In reality, the soft-line appeasement policy taken by Clinton against North Korea and China is what has led us to this point.......
Even better.
I think the Japanese would have to change their constitution to have nukes...or something like that.