Market conditions for the UK's big four international law firms haven't looked this good since before the credit crisis. The world's leading banks continue to set aside eye-watering sums of money to clean up the mess generated by the great financial collapse of 2008 while deal activity has picked up dramatically across the world, as evidenced by Mergermarket's half-year tables.

Symbolically, global deal value for the second quarter is the highest since 2007. The achievement of this landmark coincides with Clifford Chance (CC) finally overhauling the £1.33bn it achieved in 2007-08, by recording a 7% increase in revenue to hit £1.36bn.

Allen & Overy's (A&O) 2% revenue rise is more modest, but the firm can point to five years of revenue and profit growth. It would be surprising if the remaining two London-headquartered global giants – Linklaters and Freshfields Bruckhaus Deringer – don't record similarly robust results, even though optimism and deal activity only really returned at the start of this year.

So is it business as usual for the UK's big four, with the caveat that the last seven years have forced them to become leaner and better-managed operations?

There is certainly a more measured feel about this quartet when their strategic activity is considered. The late 1990s and early noughties were peppered with a series of mergers and subsequent partner culls. Now we are being asked to salivate over the returns on a low-cost centre in Belfast – in A&O's case – or in the case of CC the fact that "continuous improvement is increasingly embedded into our operations".

This speaks to the notion that hard-pressed clients are forcing firms to rethink how they conduct the business of law. And, to an extent, it is happening. But the downturn has unleashed another force that is surely having a more dramatic impact on international business – the coordinated global regulatory clampdown. Regulators talk to each other more than they ever did and they are handing out big fines.

Because of this, the world's biggest banks and corporates need coordinated advice from top advisers with a good spread of offices around the globe. Step forward A&O, CC, Freshfields and Linklaters. But as Barclays' recent panel review shows, the UK thoroughbreds will also be conscious of the way sustained US regulatory pressure is granting ground to their New York rivals.