Icelandic voters are casting their ballots this week whether to reopen negotiations for joining the European Union in a referendum some see as a way to protect their island against Washington’s desire to expand into the North Atlantic.

Citizens will vote on Saturday in a referendum asking “Should Iceland resume accession negotiations with the European Union?” President Donald Trump’s bellicose tone toward neighboring Greenland has been received with dead seriousness by officials in Reykjavik, who fear that their island would be a future target for American expansionism. Supporters of the proposal see EU membership as a valuable layer of defense against encroachment.