Just why does everyone keep suggesting an American branch of Torchwood? Torchwood's mandate is to defend Britain? How does an American division factor into that.
Unless, you're going to bring the mysterious Torchwood 4 into this. Torchwood 4 was the branch Jack mentioned in the pilot as having "disappeared" but was "expected to return someday." I suppose it's possible that Torchwood 4, while origianlly being somewhere in the UK could somehow end up in America when it returns.
The US Army and Air Force's mandates are to defend the United States.
Why then is there USAF and Army in Britain, Germany, etc.?
See the parallel?
Yeah, a branch of Torchwood could certainly be operating in the US for one reason or another.