連合国 "Allied Countries" is how the Allies are referred to in Japanese. I'd venture to guess that the main idea the word "Allies" as a proper noun would conjure up for most people is the large group of second world war combatants that fought the Axis and did some other stuff. Given the target audience for Persona 2, one would have to be pretty ignorant not to know this and probably of a denominator too low to pander to. But I'm a bit of a snob that way.
If the phrase said 連合国, “Allies” it would be

Additionally, I'm pretty sure "Coalition" is by far the more recognised term for the parties involved in the recent wacky adventures in the Middle East, never "Allies" as a proper noun. I'm not aware of any significant group trying to dredge up the Coalition's reputation with the term "Allies".
I was referring to “Anglo-American”.
Google “anglo-american forces” and you’ll find plenty of Iraq and WWII references, even from very reputable ones such as the Encyclopedia Britannica. This is what “anglosphere” refers to, and “Anglo-American”, while not a precise term, is not an incorrect one; it is a term that can also refer to English-speaking culture as well as someone who is an American of English stock (which is the sense used by pro-racism neo-Nazis and such; in other places, Anglo-American culture is often criticized for being overtly hip-hoppy and stuff... which is clearly not in the ethnic description). As it is, the phrase says “米英”, which certainly does “pertain to the United States and England”, which can (broadly interpreted) refer to current and former British holdings.
Looking at what Gemini has, it looks just about right.
