The Swiss bank ubs has warned that a breakup of the euro could have dire political costs. “It is also worth observing that almost no modern fiat currency monetary unions have broken up without some form of authoritarian or military government, or civil war,” it wrote in a report titled “Euro Breakup—the Consequences,” published on September 6.

“The costs are high—whether it is a strong or a weak country leaving—in purely monetary terms,” it wrote. “When the unemployment consequences are factored in, it is virtually impossible to consider a breakup scenario without some serious social consequences.”

The report pointed out that although breakups of fiat currency monetary unions are rare, history gives a dire warning. “With this degree of social dislocation, the historical parallels are unappealing,” it says.

Past instances of monetary union breakups have tended to produce one of two results. Either there was a more authoritarian government response to contain or repress the social disorder (a scenario that tended to require a change from democratic to authoritarian or military government), or alternatively, the social disorder worked with existing fault lines in society to divide the country, spilling over into civil war. These are not inevitable conclusions, but indicate that monetary union breakup is not something that can be treated as a casual issue of exchange rate policy.

Later, ubs writes: “The question is … whether a liberal democracy could withstand the social turmoil that surrounds a monetary union fracturing. We lack evidence to support the idea that it could.”

Last year, Stratfor also analyzed the possible breakup of the eurozone. It pointed out that in a scenario where a nation like Greece left the euro, the government would have to take authoritarian moves. Greece would be reintroducing its own currency, so it could immediately print more of it. No one would want to swap euros for a currency that’s about to be devalued. “Therefore,” Stratfor wrote, “the only way to get the currency circulating would be by force.”

The process “would require capital controls and shutting down banks and likely also physical force to prevent even more chaos on the streets of Athens than seen at present,” it wrote. “Once the money was locked down, the government would then forcibly convert banks’ holdings by literally replacing banks’ holdings with a similar amount in the national currency.”

More and more politicians are waking up to the fact that the eurozone must go through some radical changes before this crisis is over. But the economic changes necessary require even bigger political changes. These changes are going to force whatever succeeds the eurozone to be an authoritarian state.