The Swiss will vote Sunday on a heavily debated proposal to tighten their country’s traditional neutrality, amid fears that an expected “no” could be interpreted abroad as abandoning the cherished principle altogether.

The Swiss widely embrace their neutrality, but an initiative to enshrine a strict definition into the Alpine nation’s constitution has exposed deep disagreement over what that neutrality entails.

During the heated debate, it has appeared that Swiss identity itself was on the ballot.