The financial crisis was a wake-up call, and in 2011 the heavily indebted countries were hit by the sovereign debt crisis. Economic imbalances were large, and investors realised that a single currency does not automatically entail joint liability for sovereign debt. Yield spreads widened again. Retrospectively, we can see that the financial markets did not play the watchdog role, as they should have done.
Given the unsustainable economic policies, risk premia on the government bonds of the debt-ridden countries should never have fallen to the German level after the introduction of the euro. The economies in question are now in an adjustment process, which is all the more difficult because action was not taken at an earlier stage.