Why a German downgrade is the next logical step in the euro crisis

``A German downgrade, or threat of one, would have been unthinkable until recently. But then as this latest crisis has unfolded, the eurozone has lurched from one inevitable disaster to the next. A German downgrade would simply be the next in a long line of darkly logical events, that politicians seem incapable of anticipating, in a crisis moving irresistibly towards it logical and catastrophic conclusion.''