We cannot put our nukes to use beyond say the lunar orbit at the most. They can throw a few cheap but far more deadly rocks at us from the Oort cloud. Just being in a higher orbit with respect to the earth's is totally sufficient advantage for devastating destruction.
With sufficient access to energy, I imagine you could do Rods from God at significant fractions of c from Alpha Centauri and give Earth a serious bad time. Planetary orbits are kind of regular after all.
It reminds me of a part in The Dark Forest [1] by Liu Cixin, where a single alien probes annihilates a whole fleet of human space ships because of such big technology difference.
This series [2], btw, has transformed my view of space and space opera litterature. I have a much somber thinking about space, the theory in the books, is that there are species that want to wipe all their opponents and the only way to survive is to hide.
Another take at this is from Charles Stross in Singularity Sky [2], where a whole human fleet is again destroyed by aliens like a flick of a switch.
I know these two are science fiction, but like comment, a nuke won't save the day when aliens have been forced to live in the void for the travel time and have engines capable of taking them here.
Also, any civilization capable of harnessing the amount of energy needed for interstellar travel would have long ago destroyed themselves if they hadn't outgrown violent competition over resources. (The likelihood that few or no societies do so is the most likely answer to the Fermi paradox, and is strongly suggested by our own historical trajectory — see TFA.)
> Also, any civilization capable of harnessing the amount of energy needed for interstellar travel would have long ago destroyed themselves if they hadn't outgrown violent competition over resources.
If you replace inter-stellar with inter-continental, that might just be something that a (misguided) Aztec wise man would say when he met Cortez.
Not necessarily. I think a belligerent alien civilization might be frequently warring amongst themselves, driving various factions to flee their planet/system/local group. If transport and hiding were easier than seeking out and killing those factions, such a civilization would spread quickly, driven by their belligerence.