When it comes to currency warfare, one can be polite and gentlemanly about it, like Brazil for instance, which every day, and sometimes on several occasions during the day, will proceed to buy dollars in an attempt to keep one's own currency lower. Or one can do what the Belarus central bank just did, and officially devalue one's currency, in this case the Belarus ruble, by 56% overnight, against every currency out there.
At this point, it sucks (that is a technical term) to be holding any exposure in BYR. Luckily for those who held their "money" in the form of gold and silver, they just got an instantaneous 56% value preservation and a relative boost in their purchasing power with just one central bank announcement. Also, any and all indebted parties who have BYR-denominated debts are throwing one big party tonight, as their debt was just cut by more than half. And yes, the Greeks are jealous with envy.
From Kommersant.ru:The National Bank of Belarus (NBB) is sharply devaluing the official rate of Belarusian ruble. The exchange rate as of May 24 was set at 4,930 rubles per dollar. a decrease of 56% from the 23 May.