Shariah law is not imposed upon Muslims in places like the US and Britain because the percentage of population has not yet reached the point of implementing it. My understanding is that once 30% or so become Muslim, Islam begins pressure to implement it.
No, Buz. It's is because our constitution forbids it. The US could be 98% Muslim and still not be run by sharia law. Just like as for as many christians that want this to be a christian nation, our constituion forbids it, but you lot try and try.
"Why don't you call upon your God to strike me? Oh, I forgot it's because he's fake like Thor, so bite me" -Greydon Square