Putin launched a Special Miliary Operation for the same reason Eisenhower sent in troops to Little Rock back in 1957 to protect black Arkansas students.
But the resentment of Ukrainians towards ethnic Russians is, no doubt quite real. There is a lot of recent bad blood in that part of the world.
“it would be as if Eisenhower sent troops into Quebec to protect English-speaking American students.”
WIKI
The Reagan administration mounted a US military intervention following receipt of a formal appeal for help from the Organisation of Eastern Caribbean States, which had received a covert appeal for assistance from the Governor-General of Grenada, Paul Scoon (though he put off signing the formal letter of invitation until 26 October). President Reagan stated that he felt compelled to act due to “concerns over the 600 U.S. medical students on the island” and fears of a repeat of the Iran hostage crisis, which ended less than three years earlier. According to the future United States Secretary of State Lawrence Eagleburger, who was serving as Reagan’s Under Secretary of State for Political Affairs at the time of the invasion, the prime motivation for the US intervention was to “get rid” of the coup leader Hudson Austin, and the students were the pretext.
https://en.wikipedia.org/wiki/United_States_invasion_of_Grenada