There's one answer I have used with mostly good results: "I'm not a
> transportation expert. The government got them there; let it get them out."
> (Reference to "Bring the Troops Home.")
>
A better comparison here, though, might be to a question directed towards a person holding one of Working Assets' notorious "Out of Iraq, Into Darfur" signs ( http://thedisorderofthings.files.wordpress.com/2011/03/out-of-iraq-into-darfur.jpg) if that person also claimed to be a principled anti-imperialist. It wouldn't have to be a very thoughtful or profound question, either. "WTF?" would do nicely.
I won't criticize anyone for failing to offer immediate solutions to all the world's problems. I will criticize those who offer multiple solutions, to a single problem (violent crime in this case), that are transparently incompatible in both execution and principle.
-- "Hige sceal þe heardra, heorte þe cenre, mod sceal þe mare, þe ure mægen lytlað."