from being extracted from 8,000 North Korean spent reactor fuel rods, with 100 percent certainty.
Because Dubya's representatives suspected NK might be cheating on an extremely slow alternative process of extracting U-235 using centrifuges, Dubya decided to break Clinton's 1994 agreement with NK. Within weeks, NK broke open the seals on the fuel rods and started reprocessing them into bomb-grade plutonium. Eventually, such reprocessing may yield 30 atomic weapons a year for sale to other countries and terror groups and for threatening SK and Japan.
This brings to mind the Biblical parable of the Good Shepherd--Dubya idiotically unleashed 99 percent of NK's capacity to harm the world because NK might have been cheating on 1 percent of their nuclear capacity. Clinton would have taken out the Yongbian reprocessing facility immediately when it was restarted in 2002, but Dubya did NOTHING!
These facts come mainly from a great article the same Fred Kaplan of your OP wrote for Washington Monthly in 2004. Kaplan forecasted last weekend's events in that article, more than two years ago. It's still the most informative single piece I've read about Dubya's NK nuke fiasco. See
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=364x2368449 .