"Invasion" is great - I loved the way it represented and reinterpreted the original story. Nicole Kidman was extraordinary and Daniel Craig hit it on the head.
For me, the best part of the story, both here and in the original, as well as the 70's remake, a simple question: what price will we pay for peace and safety?
Simply put, the "body snatchers" are fascists - total control, total peace. Our way or the highway. Life as we offer it, or you're outta here!
On a more philosophical level, what's a human being?
Without going over the top, the story again puts it simply: a human being is a jumble of emotions that are capable of producing greatness and sometimes horror, but like the Parable of the Wheat and the Weeds, there's no quick remedy - any attempt to uproot the weeds will uproot the wheat, too.
So, we're more or less stuck - but it's okay, and more than okay. It's who we are, and anything less would be a loss of our humanity.
We've got to put up with the bad, in order to have the good of which we're capable.
The "body snatchers," the fascists in our midst, have it all wrong.
We are what we are, and God is at work in all things for good, and we're partners with God working all things out.