The yes-or-no referendum question is simple enough for the 265,000 or so eligible voters: Should Iceland resume accession negotiations with the European Union?
If voters reject the proposal, that's it, for a generation at least.
A yes vote would trigger the start of a negotiating process with the EU's executive branch, the European Commission, that will involve discussions on 35 areas, from the economy to human rights.
Perhaps, most importantly for Iceland, its fishing stocks in the rich North Atlantic waters will be up for discussion, and not everyone is happy about that. But some also believe the European Union could offer protections if Trump were to ever make similar threats on Iceland.
When Trump talked about US control of Greenland, particularly at the start of this year, he altered the mood in Iceland, which is just 290km away from the self-governing territory of Denmark, a longtime US ally.
The underlying worry among many in Iceland is clear - if Greenland is seized, is Iceland next?
The ensuing question is clear too - if yes, does EU membership provide a bulwark against any new Trump ambition in the North Atlantic?
Iceland's left-leaning coalition government, elected in 2024, certainly thinks so and that's largely why it moved forward the EU referendum that it had planned for next year.
EU talk is nothing new in Iceland, which formally ended its previous effort to join the bloc in 2015, largely over concerns of what membership would mean for its rich fish resources.
Joining the 27-nation EU would require Iceland joining the bloc's common fisheries policy that would allow Spanish, Dutch and other trawlers into their waters. The government has indicated it would look for a special arrangement, potentially a full opt-out from the policy.
In the final days ahead of the vote, Iceland's prime minister, Kristrun Frostadottir, has sought to remind voters there will be another referendum if and when a membership agreement with the EU has been reached.
"This is not an election about membership and not about adaptation, as there will be another referendum on an accession agreement if the result is yes," Frostadottir told a rally.
Backers of EU membership say it's best for Iceland to get closer to its European neighbours to combat issues that don't respect borders, such as climate change.
Iceland is already in the EU's frictionless single market and the Schengen free-travel zone.
Opponents say the current set-up is just right and that Iceland already enjoys all the benefits of European integration without the sovereignty compromises that inevitably will come from being a full member.
