Saudi Arabia invading Yemen. Syria invading Lebanon is I think around the ⅓ mark. Iraq invading Iran--note that Iran was the larger country then. All of these are conflicts that were intended to induce suzerainty if not outright conquest, and all of these are undeniably in what you'd call the "modern era".

Although I'll note that "modern era" is usually given as since about ~1789, which means we can throw in all of the wonderful aggression conflicts that make up World War II, such as Germany attempting to incorporate the populated bits of the USSR into its own territory, after killing off the current inhabitants of course.

> they fact they were always culturally Russian.

IIRC, he claims that Ukrainians are themselves no different from Russians, which means this gives him casus belli to incorporate all of Ukraine on the same grounds.