Note that the Monroe Doctrine effectively mitigates most of this. If USSR declares war on any nation in the Western Hemisphere, US (and subsequently UK & France) can declare war on them. This would be like shooting yourself in the foot twice :mrgreen:
Countries in W.H. as per Wikipedia:
“The Western Hemisphere consists of the Americas, the western portions of Eurasia and Africa, the extreme eastern tip of Siberia (Russia), numerous territories in Oceania, and a portion of Antarctica, while excluding some of the Aleutian Islands to the southwest of the Alaskan mainland.”
Thus, Ireland, Portugal & Spain are included.