I don't think you need world-wide law-enforcement, it'll be a big step ahead if you make owners & operators liable. You can limit exposure so nobody gets absolutely ruined, but anyone running wordpress 4.2 and getting their VPS abused for attacks currently has 0 incentive to change anything unless their website goes down. Give them a penalty of a few hundred dollars and suddenly they do. To keep things simple, collect from the hosters, they can then charge their customers, and suddenly they'll be interested in it as well, because they don't want to deal with that.
The criminals are not held liable, and neither are their enablers. There's very little chance anything will change that way.