I have to disagree. The superpower only needs to inflict pain on the other in a limited and cautious way.
It depends mostly on do this superpower see the issue as a vital, or not. Middle East is important, but not vital for both Russia and the USA. Ukraine is vital for Russia and California is vital for the USA. It means that the USA can't leave California without an all-out nuclear war, and Russia can't leave Ukraine without an all-out nuclear war.
So, if we are talking about Russia or China supporting Californian secessionists it is about a nuclear war. Or, equally, its right about Canada. If Russia and China invest significant money and efforts in Canada joining BRICS and Shanghai block - it is about deployment of Russian/Chinese IRBMs in Canada and sudden attack against US missiles, and to prevent it the USA may even use nuclear weapons (if necessary).
For example, Russia has the Zionist regime in a box, in that if the Zionist regime attempts a war on Iran, Iran will wipe the Zionist regime off of the face of the earth.
First of all, Middle East is important but not vital. Second - there are a lot of Russian citizens and Russian-speakers living in Israel. Like, say, my cousin from Kherson who left Ukraine ten years ago. Back in Ukraine he identified himself as a "Jew", in Israel he identify himself (in practical meaning) as "Russian" (and stick with other Russians). As they say: "From the river to the sea - territoriya Rusi" (meaning that United Israel should have Russian order - cruel but justful and indiscriminative). Third - Israel is playing important balancing (and sometimes pro-Russian) role in the Middle East, like the current situation in Syria.
And if America joins the Zionist regime then American bases will suffer totally unacceptable losses.
Bases are expendables anyway. Unacceptable damage is starting from 10% to 50% of population and it demands nuclear (or biological) attacks against cities. And providing Iran with such technologies might be not in the best interests of Russia. While "nuclear sharing" is still possible.
Proxy wars by America have their inconveniences!
Russia only needed to make Iran the power that now is in control over the ME, to replace the Zionist regime.
And then we'll have to deal with Iran, not with Israel. Changing Zionist regime in Israel to something more acceptable - something like a "cruel pro-Russian dictatorship" with equal rights for Jews and non-Jews may be preferable.
After all, Trump was forced to make a deal with Iran's proxies to leave the US assets alone, while handing it out to the Zionists.
As I said - Middle East is important but not vital for the USA.
Ok. Let's play a game. After collapse of dollar Ponzi scheme, and hyper-inflation, burning down everyones reserves, America suffer significant (but mostly virtual) economic problems, but it is still a mighty military power (with the second in the world nuclear arsenal). Russia and China decided to eliminate America and for this goal - to buy Canada (its government), deploy there Russian tanks and Chinese IRBMs. As their proxies they decided to use French-speaker's extremists organisations and "de-angloficate" Canada. For this goal, the only official language in Canada becomes Canadian French. The only language allowed in books and TV is French. Police and vigilants allowed to arrest, attack and kill (sometimes even commit mass murders) "
tête carrée" (English-speaking Canadians) at spot. Of course, there is US-backed rebellion against Quebec regime and, later, direct US invasion in Canada.
What kind of harm should Canadian regime cause to the USA to force them to allow China deploy nuclear weapons in Canada or allow genocide of
tête carrée.
Do you believe that ordinary WASPs in the USA can allow genocide of WASPs in Canada, with, or without Washington permission?