Actually, the nature of global warfare and the increasing decentralization of violence have been going on for over 50 years, but even now it’s not a well recognized trend. From Patrick Cockburn at independent.co.uk:
Saudi Arabia and the US’s failure to defend oil facilities has had an impact on the balance of power
The devastating attack on Saudi oil facilities by drones and missiles not only transforms the balance of military power in the Middle East, but marks a change in the nature of warfare globally.
On the morning of 14 September, 18 drones and seven cruise missiles – all cheap and unsophisticated compared to modern military aircraft – disabled half of Saudi Arabia’s crude oil production and raised the world price of oil by 20 per cent.
This happened despite the Saudis spending $67.6bn (£54bn) on their defence budget last year, much of it on vastly expensive aircraft and air defence systems, which notably failed to stop the attack. The US defence budget stands at $750bn (£600.2bn), and its intelligence budget at $85bn (£68bn), but the US forces in the Gulf did not know what was happening until it was all over.
Excuses advanced for this failure include the drones flying too low to be detected and unfairly coming from a direction different from the one that might have been expected. Such explanations sound pathetic when set against the proud boasts of the arms manufacturers and military commanders about the effectiveness of their weapons systems.
The Saudis never cease to amuse. Years after bombarding civilian infrastructure and murdering people in Yemen and spending huge amounts of $, they have little to show for it in terms of captured territory. Most of the territory they captured was taken over by the UAE’s Southern Yemeni separatist allies anyway, and the January 2018 toppling of Hadi from Aden itself makes their puppet a twice-rejected and illegitimate leader following the November 2014 ouster of the stooge from Sanaa too.
Yemen is turning into S. Arabia’s Vietnam and I doubt they’ll be any smarter about it than the US was about Vietnam.