[Edited to make it more understandable question]
What if all nation use only a one currency or one global currency?, What will happen to our world?, What is the effect of every nation's or every country economy?, It can make people's unite each other?Any opinion.

for this to happen one world currency
there is going to be one leader worldwide
or else it would war and chaos
but its frightening to see that one world currency and one leader above all
I guess that will somewhat signal the beginning of the end of the world and so I hope Bitcoin will not turn out to be that one currency per the current global acceptance rate.