It starts out un-alarmingly. The optimism of German consumers weakens somewhat, according to the forward-looking Gfk survey, conducted on a monthly basis for the European Commission. So the overall index fell to 8.6 for September, from 8.9 in August. It was the first decline since January 2013.

The index bottomed in late 2008 below 2, after a breathtaking crash during the financial crisis. In late 2007, it had hovered above 9. Early 2014 was the first time since the prior bubble that the index broke above 8. And August’s level of 8.9 represented an “extremely optimistic economic outlook,” as Gfk calls it. German consumers have been feeling good, and according to the headline index, they’re still feeling good up there somewhere in the rarefied air above 8.

But beneath the surface, there is serious trouble. Gfk reports that the sub-index of economic expectations, “in light of the intensified state of international affairs, completely collapses.”

It plunged 35.5 points to 10.4. The worst monthly plunge since the beginning of the survey in 1980. In a single month, it nearly wiped out all the gains of the boom of the last 12 months. Gfk cites the escalation of the situation in Iraq, Israel, the Eastern Ukraine, and particularly “the faster rotating sanctions spiral with Russia.”

Since there appears to be no sustainable solution to any of the trouble spots, consumers are showing increased uncertainty about the possible consequences for the German economy, Gfk reports. “Particularly the sanctions against Russia, which have already hit exports noticeably, could become a real danger for the German economy.”

The two sub-indices for income expectations and propensity to spend have been spared so far this type of brutal collapse, though they both fell from their lofty perches. Income expectations hit an all-time record in August. But for September, the index dropped 4.6 points to 50.1. The propensity to spend dropped 1.7 points to 49.3. At these levels, both are still “relatively robust.”

Gfk credits “the continued stable domestic conditions, stable employment levels, good income development, and low inflation” for limiting so far the impact of collapsing economic expectations on income expectations and the propensity to spend.

ECB President Mario Draghi, along with inflation mongers in the new French government, at the Fed, on Wall Street, and elsewhere should take note: inflation, as the report points out repeatedly, is important to Germans. Watch what happens to German consumer attitudes – and spending – if you steal their income and scarce savings one bite at a time.

But dark clouds have already appeared over German consumer spending: Gfk cites the increase in the propensity to save in August as “the first indicator that the consumer will be more careful in the future and that the impulses for the propensity to consume could decline.”

For this still “relatively robust” propensity to spend to continue, “it is necessary from the consumer’s point of view, that the situation in the crisis regions does not escalate further, but that sustainable solutions are found.” Gfk then warns: “If domestic conditions deteriorate significantly in the wake of a possible further escalation, difficult times loom ahead for the economy.”

Given the new economic malaise in Germany [Sanctions Are Eating their Lunch: Russian CEO Begs for Bailout, German Economy Swoons], any decline in consumer spending, which grew at a measly 0.9% last year, could wreak real havoc, not just in Germany, but also in its most critical trading partner France, in Italy, and other struggling economies in the Eurozone. German consumers are infamous for closing their wallets. And if they do it again, after they finally started spending more, they’d quickly prick any remaining hopes for a “recovery” in the Eurozone.

Even the folks at the German Ministry of Finance very belatedly admit that the sanctions spiral caused Germany’s current economic swoon, as if they’d finally found my site where I’ve been explaining this to them with utmost patience for months. Hilarity ensued. Read…. This Is what Happens when otherwise Competent, Diligent, and Hard-Nosed Bureaucrats Fail to Read my Stuff