Legalize weed

How about it, Americans? Lets do it and tax the hell out of it.

After flooding the world with worthless derivatives, clusterbombs and crappy movies Washington could try and legalize (US) weed worldwide, demand all weed transactions globally to be settled in US dollars and have the likes of JP Morgan en Goldman Sachs changed not into banks but into giant weed farm clearhouses.

What kind of revenue would this generate and could it work?

Not trying to start an ideological discussion. Only econ.

Ok sure its crazy but seriously, why not?