There are limits to what even the ECB  can do. The ECB’s power derives from its ability to print, or destroy, theoretically infinite amounts of money.  If, for example, the ECB wanted the euro to weaken, all it would need to do is print up whatever number of billion euros, and sell them in the forex market, and the euro would weaken.  If the ECB wanted to stop inflation, all it would have to do is raise interest rates by whatever number of per cent (another way of saying destroy money) and inflation would fall.  At their most effective, central banks are like…