In Russian geostrategic gaming these are two of its main allies.I would say that demographics are a major factor as well, as rapid population growth has resulted in large numbers of young people. In addition, there are rising expectations which can't be met regardless of who the political leadership are.
I wouldn't want to give odds on Iran falling over, or how it would play out. The social conditions there are very different from the Arab world, although there are some similarities. I wouldn't consider it to be inconceivable though.
What I do know is that if Iran, Venezuela, and Nigeria, the latter two of which are looking particularly shaky, all fall over at the same time that will take a big chunk of the world's oil reserves off the market at the same time. While I can see Russia and Saudi Arabia feeling rather smug at the idea of skyrocketing oil prices and a sudden increase in their own indispensability, I don't think the rest of the world would look forward to the kick in the economic groin this would cause.
There aren't that many members of the Axis of Awfulness- Russia, China, North Korea, Iran, Cuba, Venezuala..
China is probably unimpressed with Trump, Putins placeman, starting a trade war with them.
North Korea will follow China.
Iran is overcommitted in Syria, while it's domestic politics are shaky.
Venezuala and Cuba are basket cases.
The world is coming off its petrochemical addiction quite quickly, so taking more oil off the market MAY increase the price to Russia and Saudi benefit, but I think you will see fairly rapid diversification and more shale oil coming on stream very quickly.