a "strong currency" policy without the backing of a strong economy is a foolish policy, and the policy that the US has been pursuing as if having a "strong currency" magically creates the strong economy that is required to make a "strong currency" policy sustainable.
Of course, whether it will or not, that is always an open question, but I reckon it can be done. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.