With the end of the Bretton Woods regime on August 13th 1971, when the US decided to leave behind the era of Gold Exchange Standard, Western European countries were forced to give up the convertibility of their currencies, and exchange rates started to float. In the wake of such change, financial and monetary stability seemed to be suddenly at stake. Europe reacted with the Werner plan, put in place in 1973. Europe entered a new era, and looked for a new equilibrium. The birth of the EMS scheme (centered on the D-Mark) appeared to create this sought after stability. It developed a new figurative currency, the ECU. The Lehman crisis (September 2008) was the spark for a debt crisis that rapidly enveloped banks, non financial corporations, households and last but not least, national governments. Initially it was primarily the banking sector's stability that was at stake, worldwide and in Europe. Governments reacted by supporting the banking system (with guarantees, capital and debt). In order to avoid a deep recession, most countries supported collapsing demand by expanding public spending. Those actions stretched public finances and increased sovereign deficits and debts. Indeed, rather than to act in concert, each Eurozone member decided to support its ‘own’ banks. This choice was perceived by markets as the end of the European convergence: the risk was shifting from commercial (banks) to sovereigns (states), but in an uneven manner: each one was on its own. It is therefore up to political leaders to create the conditions for a stronger euro zone. True financial integration is a necessary precondition, but it will prove to be insufficient and unsustainable if national political leaders remain reluctant to undertake bolder steps towards closer fiscal and political integration. If political leaders are tempted simply to ring-fence individual countries from the fallout of developments in other euro zone member nations, the euro zone will likely remain stuck in a no man's land, economically and politically vulnerable.