This question assumes that spilling blood is always evil. It assumes that God couldn't have a redeeming, miraculous, loving intent in cutting off a life or even an entire culture. The question presumes to judge God's actions as good or evil based on the outcomes that we can perceive. But our perspective is SO limited!

Sometimes my "good" decisions turn out to be destructive. Some of my biggest "mistakes" turned into amazing blessings. Like Midas of old, we usually have little understanding of what a decision's repercussions will be.

The Bible says that God is good and kind and loving all the time. Not even a sparrow falls to the ground without His notice. No... God is certainly not bloodthirsty. He just has a perspective and strategy that's way bigger than I can imagine.

One reason God would allow death to come to this culture is His promise that we will reap what we sow. The swords He is sending against this culture are definitely part of the readout of that promise.

Jeremiah 48:10