"A source close to Russian President Vladimir Putin told me that the Russians have warned Turkish President Recep Tayyip Erdogan that Moscow is prepared to use tactical nuclear weapons if necessary to save their troops in the face of a Turkish-Saudi onslaught. Since Turkey is a member of NATO, any such conflict could quickly escalate into a full-scale nuclear confrontation.
Given Erdogan’s megalomania or mental instability and the aggressiveness and inexperience of Saudi Prince Mohammad bin Salman (defense minister and son of King Salman), the only person who probably can stop a Turkish-Saudi invasion is President Obama. But I’m told that he has been unwilling to flatly prohibit such an intervention, though he has sought to calm Erdogan down and made clear that the U.S. military would not join the invasion.
So far, Erdogan has limited Turkey’s direct military attacks on Syria to cross-border shelling against U.S.-backed Kurdish forces that have seized territory from the Islamic State (also known as ISIS) in northern Syria. Turkey considers the Kurdish fighters, known as YPG, to be terrorists but the U.S. government sees them as valuable allies in the fight against Islamic State terrorists, an Al Qaeda spinoff that controls large swaths of Syria and Iraq." Robert Parry
The status of the supposed letter to Kerry from six senators is still unclear to me so I have removed it. OTOH the Parry article can stand by itself. pl