by whichever group wanted to arm them. The British when they wanted to make trouble for the French for example. Then it's someone else and like so many of the factions in the Middle East after awhile it is like a mercenary situation going to the highest bidder. The British fought hard to foment trouble for the French any way they could despite supposedly being "allies". That is not to say there weren't British officials who warned Churchill, ones before him also, what constantly playing factions off against each other would lead to long term.
The arrogance of Churchill and the British "upper crust" at large had them thinking that, despite agreeing to the Atlantic Charter, they were going to be able to hang onto their "empire" after WW2 and that colonialism could continue apace. But the warnings of wiser people went unheeded and the arrogance of past projections of power and influence was the basis for their policy. They were incredibly stupid to think that the various factions would somehow just "work it all out" among themselves. It was incredibly stupid of Churchill etc. to not realize that these groups they armed and set against others wouldn't look to other sources for weapons and support if the British, French, Americans etc. stopped sending them.
So here we are today. Still with armed factions going against each other and still the motivator for every move by the West is oil and influence around it. Given the history of the last many, many decades the Druze will attack those who attacked them. Then their will be counterattack. Lather, rinse, repeat. Over and over and over again. All of these factions were told and shown over and over again that seeking weapons and aid and being willing to battle was the way to more aid, protection etc. They became something to be used as far as the outside world has been concerned.