This continues to baffle me.  I've never signed on to any agreement with my government, but I'm beholden to the law nevertheless.  If anyone can just choose to be beholden to the law or not, the law isn't really law at all, but some kind of gentleman's agreement.  Which is hardly any way to go about ensuring the rights of the citiens of the world.  And then how is the ICC legitimate if there are no legitimate international laws?  

Drives me crazy.  

Those who can make you believe absurdities can make you commit atrocities. -Voltaire