We encounter aliens, now what?
Suppose a few hundred years from now humanity is a space-faring race, we've explored most of the galaxy (by probe) and found that in a good thousand light years or so in every direction we're the only race to have spacecraft, let alone FTL technology. The alien races in our vicinity (i.e. the intelligent tool using kind) are at best at an equivalent to our Renaissance, progressed enough to have politics, militaries and limited scientific/industrial capabilities, but can't hold a candle to our own.
You're the captain of ship sent to the most advanced alien world in the region and the decisions you make will determine the first contact policy for the rising human empire. High command has made it clear that they don't want this world becoming a problem down the line, your orders are to subjugate or destroy, how do you proceed?
If you choose to subjugate how do you go about it?
Remember this world must not become a problem for the human empire down the line, the world must be safe for humans to live on and rule without fear of reprisal or rebellion.
Deadlier, Sillier and more Perverted.