'US military, "properly trained", same sentence? For what values of "properly trained"???'
US military on the pointy end will kill/deny you resources quite efficiently, while the support train can fudge training numbers and thus do not have the actually training - they also tend to be a mixed bag of personality types, so they can drag down the kill ratio. "We Train Hard, so War is Easy" combined with Unit tradition of 'It is not your duty to die for your country, there is no honor in that, it's to make the other sonuvabitch die for his!' (pretty sure Patton quote)
Figure in that there are now several generations of retired combat vets - woe betides the side they are not on come de la Revolucion. Historic ref: Revolutionary Armies of Washington et al had high levels of British trained combat vets from the French-Indian wars, who were further trained in frontier fighting tactics borrowed from the war. British didn't have many blooded troops until they brought in the Hessians, and were slow to react to creative attacks by the so-called rustic colonials. Having all these vets around not happy with Federal policies, should make folks thoughtful. It won't, because humans are content to repeat history because they have somewhat superior intellect compared to the masses, therefore consider it inconceivable that they would reap the same results as their more-backward political predecessors in the past.
As for uncontrolled weapons purchasing... I'm at odds with the NRA (paid member) in the belief NO ONE should be allowed to own a firearms unless they have completed a proficiency range test and a strong Law & Safety test - make them work for it if they want it - I want zero accidents and responsibility with weapons ownership. But what do I know?
The London argument doesn't really apply with the recent truck attack on that bridge - trained citizen weapons ownership would have enabled two better possible outcomes: Armed Concerned Citizen stops attack with personal weapon or more likely, blocking the sonuvabitch trucker in a hurry, because Mr. Crazed Trucker ain't getting position on me by cheating. Isn't nice and I do not have to tolerate bad behavior in polite society.
Enough rambling, lack of sleep is making me see things..
tl:dr rambling opinions not in any particular order.