Countries will act within bands based on their options and status, but no one country will take the same tack at the same time because of their different economic positions. In other words, a country can’t merely turn on a switch and start a currency war of the sort people are talking about. Some don’t want to, others cannot and the rest are constrained in how they can act.
And while disruptions may happen from time to time, equilibrium is more likely to set in as each country responds slowly. So the currency game will play out in slow motion as each country adopts its preferred approach.
http://www.zerohedge.com/news/2013-02-21/visualizing-currency-wars