It took almost two years for the ECB to get over its fear of hyperinflation and finally open the spigots. If Hollande refuses to go along with this economic deal with the devil then a worst-case scenario could play out: Bank failures in Italy, Spain and Greece, and even in Germany and France, leading to high yields and crippling sovereign defaults across the eurozone. The euro would be finished. U.S. and Asian financial firms with European exposure would get hit hard, setting off a panic that would make 2008 look like a pleasant stroll along the Champs-Élysées.
To be fair, this dire scenario precludes the possibility of Hollande, who is known in the French parliament to be a strong consensus builder, from changing tack at some point. Socialist politicians usually ramp up the rhetoric against banks on the campaign trail to pick up votes, so Hollande's hatred of the financial system may just be his way of playing to his base. Once in office, he might actually tone it down. Wall Street certainly hopes he does.