Maybe you are not familiar with the EEA. Iceland already has access to the European single market. Just like Norway, who doesn't seem motivated to join the EU, either.
And how does that relate to what I wrote?
It is unclear to me how changing from EEA to EU membership somehow protects Iceland (a founding NATO member) against being 'forced to limit their business dealings with Russia'. That is how it relates. Feel free to help me connect the dots.
It was a added downside to the comment I was replying to.