its more like alliances in the americas is a giant venn diagram of sub alliances. its not really a black and white picture on country alliance. there are sub allliances that may only include 4 countries, then a few of those countries may have a seperate alliamce with 6 othera and such.

for example, most countries in the Americas are defended by monroe doctrine in the case of outside of americas colonization. some of these alliamces are basically conditional alliances fighting a specific cause.