Police cuts: Is the force drowning or shroud-waving?
The warning to the home secretary that cuts to police budgets might "reduce very significantly" the UK's ability to respond to a Paris-style terror attack is seen by senior officers as a trump card in their campaign to change the chancellor's mind before next week's spending review.
It is thought George Osborne is considering reductions of around 20% in the amount spent on the police in England and Wales. That, a leaked document from a senior officer argues, is more than double what the force could withstand if it is to offer a viable response to multiple simultaneous terrorist incidents such as we saw across Paris a week ago.
How much credence will the home secretary and, more importantly, the chancellor give to these warnings? After all, the prime minister has already announced that the police's counter-terrorism budget will be protected.
The leaked note, entitled "Implications of the Paris Attack for UK Preparedness", says further losses in officer numbers "will severely impact our surge capacity" in respect of a major terrorist incident. So what is "surge capacity"?
The phrase is usually applied in a medical situation: it relates to the ability of health services to respond to a major emergency or disaster. The senior officer, however, is using it in the context of police response to a major terror incident, the first time I have seen the phrase employed in this way.
Clearly, if you have multiple terror attacks in different locations over a very short period, it is going to require an extraordinary response from police and, potentially, the military.
The suggestion, though, that thousands of bobbies with truncheons might be mobilised to respond to such an incident does not make sense. Surge capacity must mean armed police officers.
The latest figures show there are 5,875 firearms officers in England and Wales, down more than 1,000 from 2009. The number has fallen as demand for their services has declined. Violent crime has fallen significantly and last year armed officers were only required to fire their weapons on two occasions.
With less than 5% of police officers trained to confront tooled up terrorists, one might ask why chief constables don't train more, if that is what they really need.
I heard former Home Secretary Lord Reid on BBC Radio 4 this morning pointing out that there were 115,000 police deployed in Paris last weekend - equal, he suggested, to what the entire force in England and Wales might be if the cuts go ahead.
Policing traditions in France, however, are very different from Britain. The French have long had a penchant for men in uniform with guns.
The Gendarmerie Nationale, numbering some 98,000 armed officers, is part of the armed forces and therefore under the umbrella of the Ministry of Defence - although it is now part of the Ministry of the Interior - and deals with serious crime on a national scale. The Police Nationale, with a further 144,000 officers routinely carrying pistols, operates in cities and large towns. And then there is the Compagnie Republicaine de la Sécurité (CRS), numbering around 13,000, who are used for riot control and the re-establishment of order.
In addition to all of that, the French have Police Municipal - around 18,000 unarmed local officers in 3,500 communities.
In the UK, the principles of Sir Robert Peel apply to policing - a focus on minimal use of force and the notion that officers are "only members of the public who are paid to give full-time attention to duties which are incumbent on every citizen". There is little public support for officers to be routinely armed.
Cuts to police numbers, however, have caused concern among police, some politicians and members of the public. People tend to equate the size of the force with its ability to protect us from harm - more cops, less crime. While there must be some truth in this idea, there is really very little correlation between the number of officers we have and the risk of being a crime victim.
Broadly, crime rose in Britain in the 50 years after World War Two and has since fallen consistently. Police numbers rose as crime increased, but continued to rise as crime started to decline in the mid-90s - peaking at about 144,000 in England and Wales in 2009.
Since then we have seen a reduction of about 20,000 police officers - the current figure for England and Wales is 124,264, not including police and community support officers. Northern Ireland has 6,780 officers and Scotland has 17,234.
So would further reductions on police numbers put the country's safety in jeopardy? This week the Institute of Fiscal Studies looked at police budgets in a report called "Funding the Thin Blue Line". The report concluded that "cuts to police spending since 2010-11 have been large enough to reduce spending per person by 2014-15 roughly back to the level it was in 2002-03".
But is that such a problem? After all, the amount of crime reported to police has fallen by more than a quarter since then. In 2002-03 they dealt with 5.9 million incidents. In the last year it was just 4.3 million. That aspect of their work has diminished greatly and I don't recall police complaining their budgets weren't big enough to keep us safe back then.
The police argument is that while crime has fallen, other parts of their work have grown. As the service of last resort, they are increasingly expected to deal with people with mental health problems, anxieties over anti-social behaviour, domestic disputes and other non-criminal activity.
A significant part of police time is now spent monitoring serious offenders in the community as well as protecting vulnerable individuals. Senior officers would also point to the changing risk from cyber-crime and, indeed, terrorism.
These are legitimate points. The debate needs to be around the question of what the police are for. Theresa May famously told senior officers that their job was "nothing more, and nothing less, than to cut crime". But most police and crime commissioners would say that is simplistic.
The public expect police to do much more than deal with crime. A lost child or a confused old gentleman, a burst water main, inconsiderate parking, noisy neighbours - are we really saying that the police should stop worrying about these unless they are demonstrated to "cut crime"?
And then there is the risk from a Paris-style terrorist attack. Of course, we could reconfigure our police forces to be ready to respond to simultaneous shootings and bombings. We could train and arm tens of thousands more officers so there is "surge capacity" in every major town and city in the UK.
But that would mark a revolution in Britain's attitude towards policing - a change for which there is little evidence of public support.