Is it all over? That's certainly the impression being given by the French and Japanese governments following the arrest and ouster of Nissan Motor Co. Chairman Carlos Ghosn.

Hours after the Japanese company's board voted to remove him due to allegations of misconduct, the two countries' finance and economy ministers met and pledged support for the alliance between Nissan and Renault SA, where Ghosn is still nominally chairman and chief executive officer.

Perhaps this particular body can be swept under the carpet and both sides can agree to go about business as usual. But the tensions that the past week has laid bare aren't going to vanish so easily — if anything, they've been exacerbated. So despite the warm words from politicians, it's worth war-gaming what Renault and Nissan could do if they wanted to push this situation toward a breaking point. The events that took place Nov. 19 show that what's unthinkable is no longer quite the same as what's impossible.