WW II began for the United States with an attack on Hawaii. Under the NATO agreement, Articles 5 & 6, if Russia were to attack Hawaii, NATO might not be required to defend the U. S, as Hawaii is not part of North America. Some have thought that under Article 4, NATO could defend the U.S. See:
https://www.msn.com/en-us/news/world/vladimir-putin-can-exploit-this-nato-loophole-to-attack-the-us-and-not-trigger-article-5/ar-BB1kNaWz?ocid=msedgdhp&pc=DCTS&cvid=a3d7633209e6419d97de75029ff68e0b&ei=17