In "The Blood White Baron", about Mongolia during the Russian Civil War, there is off-hand mention of Mongolian currency being linked to the Mexican dollar, "a key international currency at the time". This seems very strange to me, given that Mexico was only just finishing up a decade long period of marked instability from their revolution, and unrest would continue for some years after as well.
So is this true? An exaggeration? And if there is some truth to it, why Mexico of all places? Just seems very strange to me, so I'm wondering why and how this came to be.
They're actually referring to the Spanish dollar, which was a standard currency in many countries during the empire. Spain's American colonies produced upwards of 70% of the world silver supply for a long period in the 16th and 17th centuries, so this was a fairly sensible standard. After Mexican independence, Spain's mints were cut off from American silver (the bulk of which came from Mexico). Mexico itself continued to produce, but the name for the currency gradually became the "Mexican Dollar" rather than the "Spanish Dollar" in recognition of their source.