Many market analysts consider a deeper fiscal union the only way to hold together a troubled euro zone. And while Germany continues to loudly reaffirm its long-standing opposition to shared euro zone bonds, the region is in many ways already headed towards implicit mutual responsibility for national debts. Berlin will likely come under increasing pressure to succumb, especially now that “core” European countries are entering the crosshairs of speculators .

The region’s complex TARGET2 payments system, which hosts payment flows between euro zone member states, suggests there is already a good deal of risk-sharing implicit in regional structures, not to mention the exposure the European Central Bank has to peripheral debt. That shared liability may fall short of the kind of joint risk-taking foreseen for a common bond, where one country is responsible for the non-payment of debt by another.

But analysts say the build-up of imbalances in the system – as the ECB replaced private sector lending which dried up for peripheral countries – reflects the latest in a number of crisis-fighting steps that have increased regional integration.

The tab Greece and other indebted euro zone members are accumulating at the Bundesbank via the ECB illustrates how intertwined Germany’s fate has become with those of peripheral states.

Elwin de Groot, senior market economist at Rabobank, says:

As these assets or claims and liabilities vis-a-vis other member states grow, it means you get more and more involved in each other’s business and that’s basically the same as saying that you are gradually moving towards a fiscal union.