It is possible to think that it will move from terrorism/military to where it was for decades - not allies, not friends, but relatively peaceful.
I realize that many people in the Iraqi government are the same as in Maliki's government. I also think they could well have learned that just because the Shiites are a majority and they have Iran's backing, they are not better off marginalizing the Kurds and Sunnis. The fact that they are speaking of Sunni "national guards" where the government pays for them and they are the primary force in Sunni areas is promising.
I agree with you that a truce with a new leader is more likely than with Assad - even if like you said of Iraq - the government is still fundamentally the same. I think that a truce with Assad is difficult due to his murderous actions - even if they occurred only after people rebelled against him. (The only counter I can think of is that the leader in Sudan is wanted for war crimes and the US dealt with his government and not him in the leadup to the vote that resulted in South Sudan. Both countries still have major major problems.)
As to the US bombing Syria - they are NOT speaking of bombing government installations, but ISIL. I suspect that, in fact, it will not be the US bombing here - but likely Assad - and we will "deconflict". If not Assad, it likely will be a Middleeastern force - and there are some that offered help.
I do think that what Obama is trying to do is both complicated and not easy. Months ago, the NYT printed this oped by Kerry as the administration's position which they balanced with one from McCain/Graham. http://www.nytimes.com/2014/08/30/opinion/john-kerry-the-threat-of-isis-demands-a-global-coalition.html?hp&action=click&pgtype=Homepage&module=c-column-top-span-region®ion=c-column-top-span-region&WT.nav=c-column-top-span-region&_r=0
I would assume that this is absolutely not what Obama would have chosen to be the condition of the Middleeast 6 years into his Presidency - but the real question is what happens if he does not lead. I know the American norm is to view everything as fixable and us as the ones best able to do it, but the question is what would really happen in a vacuum where we did not respond?