Who is this no so friendly military power and why are they going to assist Iceland, and why does Iceland need any protection at the moment from anyone?
What I remember about my stay in Iceland was the strong socialist and anti-American bent of the place. It was like Cuba North in some ways. There were constant protests against the US presence, nasty anti-US speeches in the Althing were so predictable you could set your watch by them.
This is more of the same. They would have complained regardless of how the notice was given.
Why did they tolerate us those many years? What are they losing now? A ton of money. If they feel vulnerable, they'll now have to field their own armed forces at their own cost. It's easy to be a pacifist and to rail at the big bad US for being such a warmongering bully when you don't have to pay a dime toward your own defense. As long as someone else is paying to keep the wolves at bay, you can indulge yourself in the vain fiction that the world would be a wonderful place if they were only as righteous, liberal, and pacifist as you (Iceland).
And Iceland's economy is largely based on fishing in rough, rough seas. They loved the free search and rescue courtesy of the US.
Not all Icelandics are anti-US. Many of them are truly wonderful people and stout allies who are very grateful for the contributions the US has made toward their security and prosperity. Unfortunately, they are discovering that this is what happens when the moonbat left gets what it prayed for.