A phoney summer calm may come to an abrupt end in September with decisions by Germany\'s Constitutional Court and the European Central Bank threatening to plunge the eurozone back into crisis. A series of high-risk dates are etched on the minds of financial analysts, first among them Thursday\'s ECB governing council meeting at which the central bank is expected to detail how and when it may step in on a larger scale to tame struggling countries\' borrowing costs. ECB chief Mario Draghi\'s statements indicating that the central bank was going to play a greater role in the eurozone\'s rescue efforts was a key reason markets kept calm throughout August. But with talk again of a Greece exit from the eurozone and predictions that Spain will need a sovereign bailout on top of help to shore up battered banks, the ECB\'s contribution to crisis-fighting is just one piece of the jigsaw. Just as important, according to analysts, is the German court ruling due on September 12 on legal challenges to the European Stability Mechanism. Any decision that holds up ratification of the new eurozone rescue fund, as well as the fiscal pact for tighter budgets, would undermine key elements of the eurozone\'s new institutional defences against the debt crisis. Also on September 12, The Netherlands holds a general election which could see the rise to power of an anti-austerity party, and the European Commission unveils legislative proposals for eurozone-wide bank supervision, the first step towards a deeper banking union. Meanwhile leaders such as German Chancellor Angela Merkel, French President Francois Hollande, Italian Prime Minister Mario Monti, Greek leader Antonis Samaras and Spain\'s Mariano Rajoy are engaging in frantic shuttle diplomacy. All the while, auditors from the International Monetary Fund, EU and ECB will be in Greece, where Samaras is trying to change the terms of a painfully-negotiated second bailout by eurozone partners. The auditors are not expected to report back on Greek finances in time for an informal meeting of finance ministers and central bankers in Cyprus on September 14-15, but rather for an October 8 meeting of the Eurogroup in Luxembourg -- and ultimately the first European Union summit of the new season on October 18-19. Natixis economists in Paris worry that \"it\'s all going to end badly.\" \"Uncompromising\" pressure on Athens in the bailout re-negotiation may force an exit on Greece and \"contrary to what is put about today in Germany or by EU leaders,\" this \"will not protect\" the other vulnerable Mediterranean countries, said Patrick Arbus. \"Investors will quickly grasp the similarity with Spain, Portugal,\" he underlined. Natixis expects eurozone states to fall short of their targets to cut their deficits, by 0.5 percent of GDP is their bet for the entire 17-state currency area this year, with Spain and Italy missing by 1.4 percentage points and Greece by even more. And with that slippage, borrowing costs are likely to rise as investors worry the countries won\'t be able to balance their books and pay their debts. That leaves Spain firmly in the firing line. With its borrowing costs rising, Madrid faces bond repayments of 26 billion euros in October and its regions are lining up for central government funds to soften the blow of budget cuts. In a Citi research note, Guillaume Menuet maintained that \"since it makes economic sense for Spain to obtain cheaper funding costs, we continue to believe that a programme will be agreed before the autumn.\" Rajoy has said he wants to learn more what the ECB plans to do to help struggling eurozone nations before deciding whether or not to seek a full bailout. Draghi has said a state adhering to a fiscal adjustment programme under a bailout would be necessary for ECB intervention on bond markets, but help is unlikely to be automatic.