Unsurprisingly, given their size and diversity, international firms in London continue to defy easy categorisation. Having entered the UK market at different times, for different reasons, with different models, picking overall themes from Legal Week's annual survey of the largest foreign firms in London, is tricky.

True, the recession has generally silenced the (not always very convincing) talk of expansion that was still evident as late as last summer. Likewise, in a more risky environment, international firms as a breed are more cautious on City mergers – with only 21% of the 72 firms surveyed saying they are open to a UK tie-up, against 45% the previous year. That's ironic given that there has probably never been a better time to pick up a bargain in the London market.

There is also very little evidence looking at the overall figures that US firms in London are retrenching in the UK. For every firm whose headcount has shrunk a little on 2008, there are two that have made substantial increases. Many practices are holding pretty much level in staffing terms.

Some of the largest practices, like White & Case, Latham & Watkins and Mayer Brown, have grown headcount since 2008 even though all three firms have made some redundancies in the UK this year. It could be that a year from now there is some headcount reduction evident at some of those firms but shrinking practices are not yet on the radar (a notable exception being Shearman, which has seen headcount come back against 2008).

Past that you need to break firms into discreet sub-groups to learn much. In general the smaller US-law focused branches of profitable Wall Street firms have seen very little change and aren't expecting much in the future.

Some of the regional US law firms with lower profitability and woolly London strategies are pulling back but in many cases they are being replaced by newer entrants who have only turned their mind to the City in earnest in the last three years. This is underlined by the substantial levels of lateral hiring still ongoing at firms like Brown Rudnick, Gibson Dunn and Crowell & Moring.

What it hasn't been is a great 12 months for developing your own talent as international firms have not promoted many London-based partners over the last 12 months. That will be neither hear nor there if it proves to be a one-off in an exceptional market. But if it continues for several more years, many US firms will be undermining their own efforts to build successful long-term businesses.

There is also a pronounced conservatism at some very fine international firms with regard to expanding their UK practices, which is surely the only thing holding them back from being stronger forces in London and Europe. London firms will be thanking their lucky stars for that.