When cheering at football/soccer matches, people will cheer ‘Nippon’, but then again, it’s hard to cheer saying the word ‘Nihon’, because in ‘Nippon’, you have the double-p (the small ‘tsu’ then the ‘po’) so it just is easier to say in a chant like that.

So, just because a person uses ‘nippon’ doesn’t mean anything about nationalism, and while these words may be used in different circumstances, I don’t see the pronunciation ‘Nihon’ disappearing or diminishing any time soon.
And you are aware that such nationalists in Japan are clearly NOT the vast majority of the people, I hope.

“Well, I’ve never Heard anyone call Nihongo “Nippongo”, but I’m planning to hightail it straight out of the country if I ever do.”

You are going to do what?

As an aside, there are a large number of cultural institutions in Japan with the word “nihon” rather than “nippon” in their name, even though they deal with subjects that may be close to the hearts and minds of nationalists. For example, the Nishinihon Bugu Katchu Kenkyusho (the West Japan Armor research center) or the Nihon Karate Do Shoto-kai. So calm down, and have a nice Golden Week.

“Nippon” does have a closer nationalist connection than “Nihon” simply as it was the one used in Dai Nippon Teikoku (Banzai!). That does not mean that the word itself, or its current resurgence, is nationalist. In fact as I noted earlier, seeing as the Japanese themselves don’t see anything overly right-wing about it, if it is a nationalist plot then it’s a pretty weak one.

I wonder what these people say next about Japan. Maybe something like “the prime minister wears a blue tie and that the proof of rising nationalism in Japan.”

I think this is Al Murray.

In reference to 大日本, I’ve often heard Japanese ask about why the UK gets to be “Great” Britain. What’s so great about it, they ask. But here, “Great” just means “Large,” not “Amazing.”

“Nihon” is generally used for more scientific names (eg Nihonzaru). “Nippon,” as has been pointed out both here and by one of the people I asked, makes a better sports chant (“Nip-pon, cha-cha-cha!” – much better than “Nihon-cha-cha-cha – people will think you are ordering tea). However the most interesting source on the difference I have found is in William Griffis’ “The Mikado’s Empire,” written in 1874. In it he notes that the double P is “a sign of careless speaking, and a lack of cultivation.” “Nihon and Yohodo of the Japanese gentleman are far more elegant than Nippon and Yoppodo of the common people. One can tell a person of cultivation by this sound.” This fits in well with the scientific use of “Nihon” (as scientists are educated), and suggests that the rise of Nippon is in part the rise of the “common” version.

日本 – にっぽん、にほん
日本海 – にほんかい (にっぽんかい is wrong)
日本国民 – にっぽんこくみん
日本人 – にほんじん、にっぽんじん
日本放送協会 – にっぽんほうそうきょうかい
日本料理 – にほんりょうり

I also noticed ‘nippon’ being used a lot when I watched TV (quite a rare occurrence) last week.

I checked the NHK pronunciation reference dictionary, and “Nippon”/”Nihon” vary in usage depending on the kanji compound.

It could just be a characteristic of the speaker, like, for example, choosing to call the country “America”, “U.S.A.”, “the United States”, “the U.S.”, or simply just “the States”.

(My TV is on in the background, and the announcer just said, “Nihon-jin”, not “Nippon-jin”)

Again, this is just based on my time and experience in Japan so take it with a grain of salt.