TO UNDERSTAND the complex relationship that Mario Draghi, head of the European Central Bank (ECB), enjoys with Germany you could do worse than flick through the archives of Bild, the country’s biggest tabloid. “Mamma Mia!” it fretted in February 2011, when Mr Draghi, then governor of Italy’s central bank, emerged as a candidate. “With Italians, inflation is a way of life, like tomato sauce with pasta.” Two months later, after a charm offensive by Mr Draghi, the paper relented, praising his Germanic rectitude and showing a picture of him under a Pickelhaube (a spiked Prussian helmet). But in August 2012, soon after Mr Draghi said he would do “whatever it takes” to save the euro, Bild said it would demand its helmet back if Mr Draghi opened the money spigot for lazy Spaniards and Italians. This week, with Mr Draghi preparing to announce plans for quantitative easing (QE)—creating money to buy sovereign debt—the tabloid warned of devaluation, doom and decline (if not, yet, inflation).

Mr Draghi was never the crazed money-printer of German nightmares. But like other central bankers, he has concluded that extraordinary economic times call for extraordinary measures. Europe’s economy is in the doldrums; it is flirting with deflation, with the oil-price collapse driving headline inflation in the euro zone down to -0.2% last month (the goal is “below, but close to, 2%”). Long-term inflation expectations are worryingly low. The ECB has deployed various unorthodox measures, including cheap financing for Europe’s banks and negative interest rates. Now Mr Draghi is reaching for the last tool in the box (the ECB’s governing council approved a QE package on January 22nd, as we went to press).

QE deeply unnerves many Germans, brought up on memories of a hard Deutschmark and fears of inflation. Today Wolfgang Schäuble, the finance minister, downplays the deflation threat. There is an added complication: in easing monetary policy, Germans fear, the ECB also eases the pressure on countries like France and Italy to reform their economies and bring their budgets under control. Look at Italy, they say: in 2011 Silvio Berlusconi, then prime minister, pledged budget cuts and structural reforms under ECB pressure, only to backtrack as soon as the bank’s intervention had cut interest rates. Investors’ anticipation of QE has already helped push many euro-zone bond yields to record lows.

The ECB’s monetary activism has riled Germany before. In 2011 two of its central bankers quit their jobs over the ECB’s intervention in bond markets. Mr Draghi’s relationship with Jens Weidmann, head of the Bundesbank, is notoriously scratchy. Mr Weidmann and his fellow German on the governing council, Sabine Lautenschläger, were expected to vote against QE this week.

What makes the QE row different, and more dangerous, are signs that Mr Draghi is losing the confidence of Angela Merkel, Germany’s chancellor. In the euro’s darkest hour in 2012, she backed Mr Draghi over the protests of Mr Weidmann, her former adviser, when the ECB approved a conditional bond-buying scheme known as OMT. But this week, in a speech in front of both men, she voiced her fears that ECB action might “result in the impression that what needs to be done in the fiscal and competitive spheres could be pushed into the background.” She has been irked by Mr Draghi’s strident demands that countries with “fiscal space” (ie, Germany) should use it to boost demand.

In most European institutions German economic clout has translated into outsized political heft. In the ECB, by contrast, its formal exercise of power is limited. Germans have just two of the 21 votes that determine the bank’s policy (and under a complex new set of rules, it will sometimes be just one). But Mr Draghi’s concessions over QE show how far German angstinfluences ECB business. The QE programme will oblige the euro zone’s national central banks to take on most of the risk of their respective governments’ debt, rather than pooling it among all 19 members. The overall size of the programme will also be limited to some €60 billion a month.

A medium-sized bazooka

Mr Draghi may guard his independence fiercely, but his political antennae are finely tuned. He knows that without German assent his own efforts will flail. Nor are his concerns as misaligned with Mrs Merkel’s as some suggest: in recent speeches he has sounded positively Teutonic in his insistence that governments must complement the ECB’s monetary policy with their own structural reforms, particularly to labour markets.

But for sceptically minded Germans, the bad news keeps piling up. Recently a German legal challenge to the OMT bond-buying programme was rejected in a preliminary opinion by the European Court of Justice’s advocate-general. On January 25th Greece looks likely to elect an explicitly anti-austerity government. The European Commission is helping several countries to exploit “flexibility” in its fiscal rules. At home, the rise of the anti-euro Alternative for Germany (AfD) party is furrowing brows in the chancellery ahead of state elections in Hamburg and Bremen. The persistence of low inflation in the euro zone gave Mr Draghi no option but to act. But it comes at a political price.

The danger is clear: that a QE package burdened by German-imposed constraint proves ineffectual and yet manages to corrode German support by its mere existence. The political damage, in other words, could turn out to outweigh the economic benefits. Germany will surely grow more hostile to future bail-outs, as well as to proposed changes to euro-zone governance. Mr Draghi may find it harder to expand the QE programme in future, as other central banks have done, or to relax its conditions. More difficult battles for the ECB’s president surely lie ahead. That Pickelhaube could yet come in useful.