But not believing Mrs T was a great mistake. The basic problem is a lack of credibility . France had the Franc Fort but miserable unemployment. This also merges into the EMU, a combination of fixed exchange rates and the next method. Under EMU, there is only one currency so fixed or floating rates are not an issue.
Interest rates apply European wide.
An independent central Bank Gives credibility to monetary policy as MP is now outside the control of government . This seemed to work for Germany, but it can't be the whole story. Japan has low inflation but a puppet Bank. In both cases, the policies are being achieved.