Japanese food and Indian food are as different from each other as Indian food and Italian food.

I'm not sure how you arrive at that opinion. Take the example of Punjabi food. It's heavily based around ghee and dairy. Does anything in Thai cuisine use butter except European style pastries?

The only major similarities I see uniting the national cuisines you listed (not regional ones) are things like curries and rice. The former arrived in Japan with European influence (where it's also common in colonial countries) and the latter isn't a feature common to all Asian cuisines (e.g. Mongolian).

Asian countries developed with more overlap in basic ingredients, cooking techniques, and historical influence networks than Europe did. Historically there were 3 influence zones in Asia. There is a lot of pickling, fermenting, salting, drying. In Asia of these techniques were more or less unified. Fish sauces from different countries are Pepsi vs Coca-Cola level of difference.

> Polish and Spanish is closer to each other than to most other asian cuisine.

I'd say Polish has a lot of similarities with Asian cuisine. Sure, both have stews and sausages, but flavor profiles are very different: acidic vs sour.

I won't be able to tell difference between gyoza & wonton if they shaped the same, but surely I can tell difference between ravioli & uszka. Uszka is IMO closer to any dumpling from Asia than to anything European.

American food contains maize, obviously. This works for multiple understandings of the word "American" :)

Pretty much, but not exactly. There is also a cooking technique (so American will be deep-fried).

Most national dishes are nothing more than adaptation of dishes from another country. Sometimes tweaks to ingredients, sometimes tweaks to techniques.

American food = contains corn (maize), in all its glorious (ex. nixtamalized, unprocessed, flour, etc.) and unholy (ex. high fructose corn syrup) forms.

Oddly enough, many Canadians use the word "American" to refer to Unitedstatesians, so presumably they'd use it to describe cuisine that same way (as in, poutine is Canadian but disco fries are American). This is extremely analogous to the Asia conversation, in that of course people know the term comes from the continental scale, but using that scale is less common, so it must be specifically invoked.

And then you've got Puerto Ricans, who are definitely US'ian but eat more like the non-US'ian Americans, so who knows what they would think of if you ask about American food, but it wouldn't surprise me if Contiguousunitedstatesian is the default (i.e., the same cuisine the Canadians would be referring to).

> I feel like as Europeans, we're as good at importing American food as America is about importing European.

What you call European food is a direct result of importing American food. Just different Americans...

American food is things like beef jerky, pemmican, maize breads.

European food is things like hamburgers, French fries, hotdogs, and apple pie.

This is getting silly

Edit: added a missing comma