Lol..Putin didn't "slap" Obama. The US won't get anywhere with token involvement. Training troops didn't do much good in Iraq. They mostly deserted and took their training to enemy factions. We shouldn't be there.
If Russia gets involved, let them. They'll have another Afghanistan to suck them dry like a mutant tick. Anti-Assad forces will buy obsolete weapons from other countries, so the Russians will have to spend resources to arm Assad. When the Soviets gained control of Afghanistan, they took control of the major urban centers and strategic military bases. Instead of paralyzing the Afghans, it united them in nationalistic pride and made them resort to guerilla warfare. Meanwhile, assuming command of the war front inspired the Afghan army to desert, mainly because the Soviets made them fight as infantry while they manned the tanks. This led the Soviets to rely on air strikes and intimidation to quell rebellions, which drew universal scorn from the rest of the world. Soviet troops occupying Afghanistan were subject to ambushes and sneak attacks, because the Afghans just wouldn't lay down for them.
Right now, the Russians are already stretched for resources due to trade embargos and sanctions. They're also identified as being atheists, which inspires the Muslims to fight godless Infidels. Unlike Odessa, there's very little pro-Russian sentiment among the Syrians, so they're going to have a costly time maintaining control if they ever manage to establish it. There's no way Russia is going to establish a power base in Syria given all these factors.
So if Vladimir Putin wants to get involved in Syria full throttle, let him. Things won't pan out like Ukraine, and soon even his most delusional, mindless supporter at home or abroad will realize what a true PHUCK UP Putin really is. One dictator throwing away blood and treasure to prop up an even more brutal dictator.