If the Dollar was officially devalued say 2 to 1 world wide. What would happen ?

[crazycharlie]

Say, They announced an official devalued dollar against most other
money. What would happen right away, say in the first few months
Two to One or more. Petrol would go up.What else?
I'd just like some opinions on this, especially the first few months.
If that is what we should "Gird our Loins" for I'd like to know a little
of what to expect?