As this week's analysis reminds us, for all the intense focus on cracking the key emerging economies, it's the vast US legal market that remains the prize London's elite can neither ignore nor seize. After all, despite high growth and large economies, the increasingly heavily lawyered legal markets of some of the most touted Asian jurisdictions are still currently worth about as much as Belgium's professional services sector. I exaggerate, but not by that much.

The pull of the US' $250bn (£158bn) market, by some estimates constituting half of the global value of legal services, means that building a credible US practice is still the overriding strategic issue for London's big four. And don't think the current frenzy in Asia is unconnected. Many City firms have concluded that a quality US union is their ideal endgame, but can probably only be secured with the additional leverage of a commanding global network.

So how is the magic circle doing on Wall Street? Talk to the average Manhattan partner and you'd think it has been a total disaster, with no progress being made over the last five years. The slow pace is hardly surprising, as it's the one jurisdiction in which scale, profitability and trade flows go against the magic circle and where the exportability of English law is of limited use. But on closer inspection, it's not that hopeless – not quite.