Russia can tolerate $20 or $25 barrel of oil, but the highy leveraged and bankrupt US fracking industry cannot, and neither can Saudi Arabia's bloated state budget.  All the Kremlin had to say was:

"We will save your bacon by giving you a higher oil price, but we want something out of the deal for ourselves.  Here is what we want.  All sanctions removed, not only from us but from Cuba, Venezuela, China, and everywhere else.  These sanctions are illegal under international law and constitute acts of war.  We have run out of patience with them.

"For Russia to give you a higher oil price, we also require that Washington reenter all the arms control agreements from which you gratuitously and unilaterally withdrew, that you remove all missiles from our borders, and that you cease your provocative war manuevers on our borders."

Faced with a highly leveraged bankrupt fracking industry, Washington would have agreed.