Also the problem of off shoring spam probably should be taken into consideration. No matter how good the plan is if a country is willing not to enforce it there will be a problem. I read a study recently that analyzed where spam destination sites were hosted (where the link in the spam message takes you) and 70% was in China.
http://www.businessweek.com/technology/content/may2004/tc20040517_1934_tc058.htm