Babylon 5 and others showed how that can be done by spacefaring species. Mass drivers routinely used to send cargo between satellites and ships get used to throw mass at high speeds onto planets, destroying them like multiple major meteor strikes would at low cost to the space farers.
I think the threat of this was used in “The Moon is a Harsh Mistress” to get independence from Earth.
That book is just one of many to point out what I am describing. I was thinking of it and the others when I posted.