If they could get here, then they are more technically advanced and probably can do what they wish with us.
If they are anything like humans, then I wouldn’t bet on our survival. I cite the historic record when one technologically superior human population encountered one less technologically advanced. Invariably the more technically advanced attempted to annihilate the lesser, often successfully. From the Biblical wars of the Israelites against the whole uncircumcised world around them to our own Indian wars, population cleansing was the policy throughout known world history. Many times it was about land or some other natural resource wanted by the the more technically advanced culture.
Other times it was simply in order to eradicate people with different belief systems, such as the encounters between the Europeans—especially the Spaniards—and the aboriginals of the New World (and the Moors, and the Jews, and the Protestants…), or the National Socialists and the European Jewish population, or the eradication of democratic Kampucheans under Pol Pot, or the religious war between the the Hutus and the Tutsis, or the cleansing that is going on right now by the Muslim Sudanese government against the Christian tribes in Darfour. Or the sizzling crisis between the radically conservative, fundamentalist Muslims and the western developed nations and their allies—again, a promise of complete, thorough annihilation.
Why should aliens be any different? Why should they deal when all they have to do is take? After all, we aren’t them or probably anything like them. It’s very easy to kill other animals once you can convince yourself that they are lower in the in the evolutionary scheme, or without souls, or whatever.
We can only hope that, along with their technical advancements, they are advanced in other ways as well—and are nothing like us.