THE CHANCELLOR of Germany, Angela Merkel, paid a visit to Greece on Tuesday, and it was not an altogether happy occasion. Though Greece’s prime minister, Antonis Samaras, welcomed his guest and thanked her for Germany’s aid in keeping the Greek economy afloat, thousands demonstrated against Ms. Merkel, blaming her for the austerity programs Greece has had to impose in exchange for German credit.

Yet these protests were tepid compared to the chaotic scenes Greeks have witnessed during the crisis, none of which are more disturbing than the attacks on immigrants administered by a thuggish new far-right party, Golden Dawn. Alas, as Greece’s economic growth rate goes down, Golden Dawn’s popularity goes up. Already in possession of the fifth-largest bloc of seats in the Greek parliament, Golden Dawn would rise to third if elections were held today, polls say. The party has taken to distributing free groceries on the streets of Athens, where it also sometimes functions as a de facto police force.

Clearly, Europe’s grinding economic crisis is taking a toll on political stability, and not only in Greece. Spain, too, has been hit by strikes, and cries for independence are increasing across wealthy, linguistically distinct Catalonia, where regional president Artur Mas called for early elections on Nov. 25 after the Madrid central government refused to grant more financial autonomy. Tired of subsidizing the rest of Spain, Catalonians apparently view their compatriots with some of the same resentment that Ms. Merkel’s people have focused on the Greeks.

We don’t mean to draw a moral equivalence between the Catalonian independence movement and the much different and patently repugnant Golden Dawn. Nor do we intend to exaggerate Europe’s political breakdown. Voters in Holland, for example, recently returned to power a centrist, pro-European majority despite strong bids from more extreme left- and right-wing parties. Germany itself has remained remarkably immune to ­anti-European agitation at a time when the financial burdens of the European Union are falling on its taxpayers.

The fact remains: Economic pressures that heretofore seemed to threaten cohesion among European nations are now creating fault lines within them as well. Though entirely foreseeable, this trend does not seem to have been well anticipated by the continent’s leaders, who remain focused on salvaging the euro, as if rescuing that symbol of unity were equivalent to preserving unity itself. And unity without democracy would be the worst result of all.

For Ms. Merkel and other leaders of financially solid European states, signs of political decay in Southern Europe only heighten the dilemma they already faced. The case for attaching strings to aid is, in brief, that there’s no point handing out loans to unreformed debtors. The case against doing so is that reform makes recipients miserable in the short term. Now the unrelenting demand for fiscal probity and structural reform may be driving Southern Europeans into the arms of undemocratic or unpredictable political forces — but Europe’s leaders can’t entirely abandon that demand, lest they seem to appease the foes of unity and democracy. As always, Ms. Merkel and company must strike a balance, remembering that European unity, solvency and, above all, democracy are at stake.