Prospective defence
...really hard to defend against: it's the teenagers...
You need to eliminate the threat in order for defence to be effective. In case of this threat-class, it may be opportune and necessary to perform a broad and complete post-natal abortion. This will eliminate the entire class of threat in less than 20 years.
And since this, as indicated, is the 'most prevalent threat actor', it must be deemed crucial to take action now and look forward to a threatless future where teenagers no longer can roam and question the old generation's status quo.