No, Russia's combat operations against the Syrian rebels in defense of the Syrian government -- no matter who is sponsoring those rebels -- do not constitute an attack on the USA. But your question begs a bigger question: What are we doing backing rebels against a sovereign nation? That's what the Soviets used to do, and we used to defend the legitimate governments against the Soviet-backed revolutionaries. Now we are the ones sponsoring insurgents and the Russians are defending a legitimate government.
Our misguided foreign policy over the past 15 years has yielded nothing by chaos and destruction. We toppled three secular dictators in the Muslim world, bad guys all. The Egyptians rescued their nation from the abyss, but the vacuums in Iraq and Libya were filled by stone age Mohammedans who are now the Mediterranean world on fire. This is a mess of our making, and a monument to hubris and naivete on both sides of the aisle.
“What are we doing backing rebels against a sovereign nation? “
Because Obama wants an Iran clone where Syria used to be