Using Putan's Logic

Putin claims that since Ukraine was once part of the Soviet Union, it belongs to Russia.

Well, the United States is part of the North American continent.

This was once part of the supercontinent,  Pangea.

Pangea was, of course, part of the Earth.

The Earth is part of the Solar System.

This is part of the Milky Way galaxy.

This, in turn,  is part of the Universe.

Therefore, friends and neighbors, the Universe belongs to the United States.

Sorry, Putin.