A political splintering of the eurozone could lead to a collapse of the euro currency, says Jens Nordvig, head of currency strategy at Nomura."I think the whole eurozone is now essentially tied together by all these types of backstops from the [European Central Bank and] from the European Stability Mechanism," he told CNBC."But, all these backstops rely on some kind of political cooperation. If that political cooperation breaks down, then you start to have problems with the eurozone again. The biggest risk to the euro is politics."While Nordvig paints a doomsday scenario for the currency, it has risen against the dollar over the past year."We've moved from a financial crisis, where we had to worry about whether banks could fund themselves," Nordvig said. "But we have an economic and social crisis with still extremely high unemployment rates that could spill over into a political crisis."The euro won't necessarily suffer a sudden explosion, Nordvig says. "An orderly decline in the euro . . . could be necessary if these political tensions start to be more prevalent next year."The euro was little changed Wednesday after U.S. Senate leaders reached an agreement to re-open the government and raise the debt limit. But the currency could gain in the aftermath of Washington's shenanigans, experts say.The longer-term effect of the crisis is that "it's a growth shock to the economy. It’ll have a dollar-negative effect," Dan Dorrow, head of research at Faros Trading, told Bloomberg