Practical needs like "I want to take over your country, so I've decided that you are the same people as us, even though you don't feel the same"???
More or less. More likely "We are the same culture, you and I, and we should live in peace, together". But, if something is really necessary for our safety we can take it without this kind of justification. Like, say, Chechens are not (by in-Russian standards) Russians (actually, Nohchi isn't even an indoeuropean language), but Chechnya is important for our safety, so, we returned it without that kind of justification.
In fact, most of Ukrainians feel that Russians and Ukrainians are the same people. Like, say, my Western Ukrainian gradma (poor villager), when saw me first time (when I was six year old boy), said: "What a nice boy! Moscowite's smartassness with Jewish courtuasity" didn't refuse to recognise me as a relative.
Nazification makes people think that they are not Russians and they should kill Russians.
Oversimplificated, there were three main ideological waves of Ukro-Nazification (all three were based on factual bullshit and propaganda)
1. In the middle of XIX century, Austria after recognisition of Czech threat, and understanding how powerful weapon could be "national-building" decided to make non-Russians from controlled by them part of Russian people (Galicians). So, they said - "You are not Russians, you are "Ukrainians" because you speak different language (not dialect of Russian). They sponsored making "Ukrainian language" from local dialect of Galician villagers. Really poor thing, practically useless for any purpose short of singing folk songs. What is even more important - for a poor and narrow-mind Galician villager everyone (including Moscowites, Jews, Poles and even "Ukrainians from Poltava") are aliens and Germans are "natural masters". One can use them for the violence and destruction, may be for some farming, but they can't make a tank or a gun. Really poor guys. Banderlogs or Raguls in the narrow meaning of the word. We can call it Ukronazism type I.
2. Second stage of Ukrainisation was Soviet. Extra-left communists government in 1920s saw "Great Russian Chauvinism" as the greatest threat for their national policy. You know, something like "positive discrimination" on steroids. Ukrainisation was a form of "rootinisation" and "nation-building" in Soviet Republics. So, they made "Derjavna Mova" (State's language) based not only Galician, but some other dialects, too. In fact, it, like Esperanto, is no one's first language. It is the language of bureaucratic features. State-loyal nazism is a form of loyalty to the state. "We are Ukrainians because our government said us that. We speak (sometimes), Ukrainian at job or because we demonstrate our loyalty to the current regime. It is so called "political Ukrainism" (or Ukronazism type II) and, say, Zelenskiy (Russian-speaking Jew) or Syrsky (ethnic Russian) are examples of that. After fall of the Soviet Union, political Ukrainism became just loyalty to pro-Western course.
3. Post-Soviet Ukrainian Neonazism, is a way to "Ukronazificate" mostly eastern, Russian-speaking population of the industrial, educated cosmopolitic Eastern Ukraine (Russians and "Russian-speaking Ukrainians"). Like, you know, Azov battalion/brigade/corps. It is classical western Neo-Nazism. You can't say to a man, speaking proper Russian language (usually even without any significant accent) that his language is not Russian. So, you tell him, that he is the only true Russian, while Moscowites are Mongols, Finno-Hungarians and Tatars and they are not Russians. Of course it is a lie and nazism in the modern Western understanding. We can call it Ukronazism type III.
So, that's what Russia has done to justify its bullshit.
Of course, not. The fact that New-Yorkers and Texans both are Americans isn't BS, even if North use it as an ideological justification for keeping Texas in the USA.
