Via the Australian website of the Lowy Institute, a short pithy article by a ret'd Israeli Air Force officer:http://www.lowyinterpreter.org/post/...s-to-war.aspx?

A few passages:
Tanks, combat aircraft and missiles are only as powerful as the people operating, maintaining and supporting them. And in this domain, Saudi Arabia has a very long way to go. Not much is known about the proficiency of Saudi Arabia's military as a fighting force. The only real war the Saudis have taken part in was Operation Desert Storm in 1991; and most of the fighting there was done by the US. More recently Saudi Arabia has been fighting in Yemen, but unsuccessfully so far. Foreign advisers speak about the difficulties in bringing Saudi Arabian soldiers to the desired combat readiness and proficiency.

(Concluding passage) Let me finish with a comment on 'Northern Thunder'. Exercises as large as 'Northern Thunder' take a very long time to plan and coordinate, and it also takes many months to gather the units together in one place. Yet, 'Northern Thunder' appeared in the media out of nowhere. (and nothing is known about it since it was announced). Where do you hide 350,000 troops? Are they really there?