In the movie Enemy of the State, the final scene involves a mafia standoff. Accusations of disloyalty fly as weapons point everywhere. Meanwhile the real culprit hides under a table, before skipping out the back door.

It reminds me of the standoff we are seeing as the police, politicians and parents all argue that schools are partly to blame for the rise in knife crime and drug dealing because of the increasing number of exclusions. The real culprit – the government, which has overseen rising crime and has the power to fix it – is being allowed to hide under the table and avoid responsibility. That’s not on.

School exclusions really are increasing. In part, this is owing to a rise in pupil numbers – and that will continue, as a demographic bubble gives us more teenagers over the next 10 years. But some of the rise appears to be because schools are more frequently saying they can no longer keep a child with behaviour problems. Plus, while the official exclusion rate hovers at about 0.1% of children, the rapid rise in home education suggests some headteachers are leaning on parents to voluntarily remove their child, to avoid an official exclusion.

Campaigners have argued that exclusions should be curbed as a way to reduce crime, and that a more nurturing approach should be adopted.

Some now also say that schools should get rid of their “isolation rooms”, used to remove disruptive students from class.

Teachers must have options when a 13-year-old is running around their classroom stabbing other kids in the leg with a compass, or smashing them over the head for failing to lend him a pen. Isolation rooms may be draconian for children who simply come in wearing the wrong colour socks, but they are one way to remove disruptive or violent pupils. We don’t expect doctors, nurses or train drivers to put up with abuse, why should teachers or pupils?

Exclusion, too, is not problematic as long as children have a quality school to attend elsewhere. But the crux of the matter is that they often don’t. Sadly, pupil referral units are woefully variable in availability and quality, with teachers twice as likely to be temporary or unqualified compared with mainstream schools.

There is a long road from a teenager misbehaving to them being so disruptive a school can’t keep them. At one time that road involved a lot of support and intervention. Now, with services cut to the bone, it is shorter. Two-thirds of schools have cut teaching assistants to save cash. Where they are still employed, they often cover absent teachers’ classes rather than supporting vulnerable pupils.

Then there are the cuts to youth support outside school. Since 2010, 600 youth clubs have closed. Councils now spend 69% less on youth services in the community. Free swimming pools? Gone. Music lessons? Gone. Opportunities for kids to get new role models and identify with a non-violent group? Oh, all gone.

Meanwhile, what is our new government offering? Mostly, burble about a science revolution and the need for Big Ben to bong.

A glimmer of hope emerged in the fund to provide summer holiday activities. Areas to receive these will be announced soon. Let’s see if they are a sop to constituencies with thin Conservative majorities, or a truly compelling offer.

Schools, the police and councils can’t solve a problem without resources. We can all blame each other. Or we can point at the real culprits, sitting under the table with their fingers in their ears, hoping to evade responsibility. The government must bring forward the cash to solve this problem – and do so quickly. A teenage boom is on the way.