Glance: Changes in the value of currencies

The world economy faces a new threat. Instead of a banking collapse or too much debt, fears are growing that countries are using their currencies as an economic weapon.

There have been increasing concerns around the world that countries might manipulate their exchange rates to gain an edge. A lower foreign exchange rate can make a country's exports cheaper. But one currency can fall only if another rises.

A fall in the value in one currency — in this case the yen — means another currency — for example the U.S. dollar — gets more yen for its buck.

Here is a glance at how the world's major currencies have changed over the past six months.