Its easy to say 'Let Putin have the mideast'. what it means in reality isn't good for anyone.
Syria is has been a Russian Client state for a long time so their support for Assad is understandable and not worth fighting over. That doesn't mean they should roll over the mideast unopposed. I wouldn't be opposed to a degree of shared leadership there but you have to have the right man sitting across the table from Putin to do it right.
Tell the Russians that ? do what they need to do in Syria and we will deal with Isis in our own way and own time.
Tell Putin Assad is your buddie and we understand that, so he is yours so we will go after the true state of terrorism Iran.
so Russia ? Say your good byes to Iran.
The US will form a plan, take out Iran’s nuke sites while at the same time join us in taking out the garbage.
Go in fast, do the job successfully then get out.