Splitting the Home Office
Splitting the Home Office is, if you believe John Reid, driven by a desire to focus better on counter terrorism.
If you believe the opposition, it is driven by the home secretary's desperation to shed the bits of a department which he dubbed as "not fit for purpose".
Remember though that this idea is far from new. For decades many in politics, particularly on the liberal left of politics, have argued that the minister in charge of administering justice should not be the same person as the minister for locking people up. That's the case in many European countries. The argument is that the prison and probation services are always ignored and under-resourced by home secretaries, who care much more about the police, and fending off charges that they are too soft.
Indeed, more than once in recent years, Tony Blair has made plans to do what he's done today. When the PM hatched the idea of replacing his old boss Lord Irvine with (his old flatmate) Lord Falconer as Lord Chancellor, the original idea was for him to run a Ministry of Justice. Then home secretary David Blunkett and, I believe, Lord Irvine himself fought the idea and won.