If Russia adheres to its red line it will have benefits far beyond Russia. From Patrick Lawrence at consortiumnews.com:
It is absolutely necessary that Moscow holds the line for the sake of a new security order in Europe and a sustainably stable world order in our time.

Russian Foreign Minister Sergei Lavrov, left, with President Vladimir Putin in 2017. (The Kremlin)
“They must understand,” Sergei Lavrov said in one of his many public statements last week, “that the key to everything is the guarantee that NATO will not expand eastward.”
The Russian foreign minister has repeated this thought almost ad infinitum lately. He speaks, of course, of the Biden administration and the diplomats who bear its messages to others.
Here is another of Lavrov’s recent utterances:
“We are very patient… we have been harnessing [burdens] for a very long time, and now it’s time for us to go.”
I do not know quite what Lavrov means by “harnessing burdens.” I suspect it is a translation problem, and he said something closer to “bearing burdens.” But it is perfectly clear what he means when he says it is time for Russia to go: He means it is time to advance beyond the status quo, move on from post–Cold War security arrangements that have allowed NATO, in the name of the Atlantic alliance, to aggress toward the Russian Federation’s western borders more or less at will since the Soviet Union met its end.
All that Lavrov, President Vladimir Putin and other Russian officials have said and done since the Ukraine crisis re-erupted late last year indicate one simple, hard-as-granite reality. In consequence of the many pointedly provocative moves the West, notably the U.S. and Britain, have made in Ukraine over the past year, our planet now has a brand-new red line etched upon it.
I hope Russia draws it in the deepest scarlet. As a diplomatic tactic, red lines are not very often advisable: They tend to paint the painter of the line into a corner. This one is absolutely necessary if we are to see a new security order in Europe. A new security order in Europe is essential if we are to achieve a sustainably, stable world order in our time.