"Two suggestions - reintroduce national conscription, and not just for young people, in large part to snap the population out of complacency - not sure how that would play politically!"
In the UK and US its the MILITARY who don't like conscription - they waste a lot of resources training people for 6 months so they can have undertrained, undermotivated bodies for 18 months max. Lots of bodies are only useful if you intend to refight the Somme.
If there's a problem in society why should it be dumped on the military to "solve"