The mayor's press release hails "a step change" in the way the Metropolitan Police Service (MPS) tackles gang crime in London and a "new crack down" on the problem. Dozens of suspected gang members have been arrested in raids across the capital and a small heap of statistics has been supplied, including an estimate that 250 gangs are "criminally active" of which 62 are considered "responsible for two thirds of gang-related offences."

Let's pause here for breath. It's good that the Met is renewing its efforts to deal with this issue, which is spreading, intensifying and becoming ever more ingrained in London life. The situation is intolerable. It's also good that new-ish commissioner Bernard Hogan-Howe has stressed that solving the problem requires more than throwing uniforms at it. "It is vital we work with the public, local authorities, charities and other agencies to prevent young people from joining gangs in the first place," he says. Every youth worker, mentor and gang mediator I've spoken to lately would strongly agree with that.

Yet we will have to wait and see how well the Met's new approach works in the longer term. Misdirected or mishandled police action can make matters worse by generating hostility towards officers in the very people whose trust and co-operation they most need, notably law-abiding young people who live in areas where gangs intimidate individuals and communities into silence or compliance.

Extending the widely-praised work of the anti-gun crime unit Trident, the commissioner has set up a "central Trident gang command." But some fear that counter-productive police action is more likely to come from specialised units without good local links. The commissioner says there will also be "local task forces across London," and that the new command will "work more closely with boroughs."

But how in practice will the new command work with such as plumbed-in neighbourhood police officers, local youth workers and so on to help ensure that its operations are as effective as possible? It isn't clear how the new initiative relates to the Met's Operation Connect, which embarked on a carrot-and-stick approach to gangs last year.

Will stick and carrot work in harmony or at cross-purposes? Green Party mayoral candidate Jenny Jones, concerned that stick will prevail at carrot's expense, is seeking more details, including about how partnership work will be funded in the 19 boroughs the new initiative is aimed at.

There's also the very stress on gangs and so-called gang culture to reflect on. While highly territorial and often violent rivalries between groups of youths in London are certainly becoming more widespread and worse, are those groups really as organised, fixed and sophisticated in their criminality as the term "gang" tends to suggest? It's not hard to find people working in this field who have misgivings about the deployment of the term "gang crime" to describe incidents that I'm told often arise from ongoing neighbourhood feuds whose origins even those feuding sometimes struggle to identify.

Claudia Webbe, joint chair of the independent Trident Advisory Group, says she is "reassured that the MPS will avoid the oversimplification of the term 'gang', and will work with partners to protect some of the most vulnerable sections of London's communities," but the fact that she raises the issue betrays concern. Lib Dem mayoral candidate Brian Paddick says there's a danger that the new Trident unit could give gangs "a status they don't deserve," adding that "the growing problem of violent crime in London is much bigger than just gangs."

There remains a nagging sense that all concerned are still venturing into the unknown. As a 2009 report from the Centre for Crime and Justice Studies put it, "Remarkably few interventions on youth knife and gun crime, nationally and internationally, have been subjected to rigorous research and/or independent assessment." Fingers crossed that the Met's "step change" is for the better.