The news of Sir Ian Blair's departure has provoked a political row over who can "hire and fire" the head of the Metropolitan Police. I don't want to rehash the arguments both ways about Blair himself but there are some wider problems.
The biggest problem is that a lot of political power has been devolved (and yes, the Greater London Authority is a form of devolved power even though it is a metropolitan wide authority and not a "regional assembly" of the type devised as a sop to the English question) in a bad manner, with the result that in many areas power is now wielded by a hydra of national and devolved politicians. It's also a poorly kept secret that when the Scottish Parliament, Welsh Assembly and Greater London Authority were set up the widespread expectation was that they would almost permanently be controlled by Labour politicians and that Westminster-devolved conflicts would be between non-Labour Westminster governments and Labour devolved ones, not the other way round. The result is that the executives have quite significant powers in their own right and are not so vulnerable to the problems of minorities in the assemblies or even an opposition majority as on the London Assembly.
But they are also probe to following a different path from Westminster. Now this is a natural consequence of devolving power and localism (although I wish the UK media would more accurately report the Scottish Parliament and Welsh Assembly rather than just focusing on the supposed benefits of spending, stoking English jealousy). However when there are both local and national concerns - and the Metropolitan Police is not exclusively a police force for London but has various national duties as well. So it's not terribly easy to carve up accountability between the Mayor of London and the Home Secretary. It can work if they're cut from the same political cloth, but when they're not (and this applied as much to Ken Livingstone as to Boris Johnson) then clashes and divided confidence are inevitable. It's not a terribly workable arrangement in the long run.
Is there an obvious solution? It's a lot harder to separate out overlap services than is often thought (a problem that also comes up with Welsh devolution because of large numbers in the borders) or to arrange things so that the same party always controls all the relevant posts (and, as Ken Livingstone demonstrated and Boris Johnson will soon do as well, just being from the same party as the Westminster government does not guarantee unity), especially when so many elections are contested as a chance to make a mid-term protest against the Westminster government. It is often forgotten that the 2004 Mayoral election was the only time a London authority election was won by the party in power at Westminster since 1949. And even that was down to Livingstone returning to Labour rather than running again as an Independent. Whether this pattern will change remains to be seen, but it is not an encouraging precedent. So what is the solution?