I’m not convinced “Russia” wants to steal Ukraine.
The average Russian person doesn’t want Ukraine - they think they should be “reunited” but not forcibly.
The Russian governmental establishment wants Ukraine for historical reasons.
Russia - or to be more specific Muscowy - has a historical “concept” of itself as
1. The uniter of all the East Slavs
2. Inheritors of the Constantinople empire
With #1 they expanded it to pan-Slavicism in the 1800s, which failed.
With #2 they expanded it to pan-Orthodoxy in the 1800s, which also failed.
From my perspective, with a less formal, less orthodox (guided less by universities) study of history,...
Not all of Russia’s subject or satellite nations are primarily Slavic (Tuva, for one example), and most non-Muslim Russians don’t care much about any particular religion. A very large percentage of people in the Federation, by the way, are Muslims. Most Russians would rather have the whole world speaking Slavic (Russian), though, and serving Russia.
Now, as expressed by some on state-owned TV, many of the upper echelon Russians are mad that Putin won’t allow them to have their army invade nations other than Ukraine. Though many of them are not old enough to have been adults before the dissolution, they are frustrated by the loss of the Soviet Union. They continue to celebrate the years of the Soviet Union as their era of greatness, even though their grandparents suffered in poor living conditions back then.
During the days of the USSR, their predecessors were not satisfied with dominating the countries of the Soviet Union. They wanted more, and they did strive for more. They, like the Chinese, don’t call it empire. But that’s what they desire.
Most of those wanting a continuation of a Russia that’s more connected and friendly with other nations of the planet are younger people who enjoy or want to enjoy that kind of connectedness (friendly) along with luxuries not enjoyed by their recent ancestors.