Any currency can be crashed if its central bank allows its private banks to lend to speculators so they can short it. That’s what happened to the Weimar Republic. If, however, the government has half a brain and decides to be sovereign over its currency and thus does not allow such irresponsible actions to occur there isn’t any problem. And any shorts in other currencies can be ignored or denied. That plus, if you have policy in effect that always keeps sufficient money in the hands of individuals to make the economy function stably and a policy that reduces retail prices to below their normal levels without punishing businesses…only a liar could say the economy was unhealthy.