I bet you'd still want to fire the missiles over the north pole to hit western Russia. A base in alaska would also be far more vulnerable to SLBMs and aircraft.
Uhh, duh? That's not the point. That's a reason TO have them there.
Of course the perimeter of our territory is most vulnerable. That's precisely why they want the perimeter of our territory to be as far away from the contiguous states as possible and why we operate in South Korea, Philippines, Guam, made Hawaii a state, etc. Hawaii was vulnerable to the Pearl Harbor attack but that's precisely why we had a base there instead of on the mainland. It was the first line of defense and an early warning for the contiguous US.