That was the advice, at the height of the Vietnam war, that Vermont Republican Senator George Aiken suggested. It looks as if Russian leader Putin has just done that in Syria. His client, President Assad, hasn't won, but is now in a better military position. Nor has the Islamic State been defeated. But Putin succeeded in gaining diplomatic leverage for Russia and actually may have helped improve the situation for negotiations.
Since the armchair analysts didn't predict Russian intervention, or Monday's announcement, I don't think anyone has a monopoly on Syria advice right now. But I think Evelyn Farkas makes some good points here.