Icelanders are voting on Saturday in a national referendum on whether to restart negotiations to join the European Union. Iceland is already closely tied to the 27-nation bloc and follows many of its laws. But many in the island nation of 400,000 people see the referendum as deciding between maintaining Iceland’s independence and seeking the stability and security that the bloc could offer.

Polls have shown a near-even split in public opinion. If Icelanders vote to resume talks, negotiators will work to hammer out a deal, which could take years. Icelanders would then vote again on whether to join the bloc officially as a member state.

Some Icelanders feel that the European Union would offer security in numbers at a time of geopolitical upheaval. Iceland sits at the threshold of the Arctic, where superpowers are vying for dominance. President Trump’s pursuit of Greenland has rattled many in Iceland.

Iceland is the only NATO member that does not have a military. Though the European Union is not a military alliance, it does have a mutual defense clause. Some worry about their financial situation — and their country’s — with inflation stubbornly high.

Many fear that the country’s economy is vulnerable to global shocks because of its small size and its dependence on tourism. Many “yes” voters think that joining one of the biggest economies in the world would bring stability. Others say they want to see what could happen in negotiations and to keep their options open.

Fishing would be a major issue: It’s a large part of Iceland’s economy, and many Icelanders are unwilling to cede any control over the nation’s waters or its industry to the European Union. “No” voters say they see the European Union as a potential threat to the country’s sovereignty. Some farmers and fishermen are worried that they could suffer under E.U. rules, in part because of increased competition from within the bloc. If the referendum passes, Iceland and the European Union will begin negotiations on membership, known as accession.