Unfortunately, they were not patient enough and jumped the gun.

The incompatibility of countries sharing a single currency goes a lot deeper than mere reforms to achieve the agreed criteria of Eurozone membership. It is cultural.  France for instance will never be able to shift away from its social model and the cradle to grave mentality of the population. Greece is another example where the culture of tax evasion will forever make the country an unreliable partner of the EZ.  The political integration necessary to make the Euro a success, will be to adopt a Teutonic discipline to fiscal rectitude. The Latin members of the Eurozone will never make the grade...Under the Euro and until the financial crisis, your "Teutonic disciple to fiscal rectitude" Germany had an average budget deficit of over 2% - larger than either the "Latin" Portugal or Spain (who ran a surplus). Now struggling Finland ran probably the largest surplus with Ireland, who received one of the largest bailouts, not far behind.  The fiscal positions of Eurozone countries prior to the crisis bear no relation to whether they did or did not have economic problems after it...The leaders of the EU project now see a far greater prize than a United States of Europe on the horizon. The concept of supra-national government, they now see, will assert human rights and 'good enough' economic well being, across not only EU member states but, especially with Obama's support, a far wider field. TTIP is the vehicle by which it will spread well outside countries the EU can reach by its own programs of expansion and bring many US based multi-nationals into the fold of cosy bureaucratic corporatist government that will ensure stability and uniformity, if not actual freedom or democracy. This is the post democracy vision of the EU's leaders: ever widening supra-national government until we have one world government. The eurozone is merely a pilot scheme, a laboratory, and lessons from it will be applied more widely to this end. It's for the greater good.