BERLIN -- Great crises often produce enduring images. For the Israeli-Palestinian conflict, this has often been a terrified child cowering behind protective parents; for 9/11 it was brave firemen rushing headlong into collapsing buildings. Last month saw what could become one of the lasting images of Europe's unending crisis: the sight of burning cars and buildings after riots outside the European Central Bank.
Greece's Syriza party has put its foot down to demand an end to the troika's agenda, and now Spain's Podemos party has risen even more quickly than Syriza to join them. This is what democracy looks like -- even the rigid, unaccountable structure of the eurozone will not be able to stop it from spreading.
If the ECB is willing to use all its available tools without limit, there is little reason to doubt that it can hit its inflation target of close to 2%. However, making that policy commitment credible remains a great challenge because of the controversy and dissent about acquiring risky government debt.
With the introduction of a negative interest rate on excess bank deposits, it has become clear that the ECB is running out of options. The institution's most important financial political tool - the interest channel - has failed in its objective to encourage lending for investment to curb deflation.