Pakistan is a nation, which, if it falls apart, if it becomes a failed state, there are nuclear weapons there and you've got terrorists there who could grab their hands onto those nuclear weapons.
Because our lungs regularly deal with carbon dioxide, they see nothing wrong with absorbing its cousin, SiO2, which can be fatal. Many dinosaurs might have died this way when a metropolis-sized asteroid or comet struck the earth 65 million years ago.