In the wake of Friday's attacks in Paris, the U.S. is urging France and Turkey to put special forces on the ground in Syria to fight ISIS alongside the 50 U.S. special operators it has already deployed. It's a case the U.S. made in person at a summit of world leaders in Turkey.
President Obama arrived in Turkey over the weekend for the G-20 meetings.
If France and Turkey agree to this, their special forces would work with Sunni Arab fighters to both help maximize the impact of coalition airstrikes and eventually retake Raqqa. While the Kurdish fighters of the People's Protection Units, known as the YPG, are a strong force, the U.S. believes that only Sunnis will be able to hold that territory once it is liberated from ISIS.
The U.S. is also looking for more help with and sharing of intelligence, surveillance and reconnaissance. The plan is to increase strikes aimed specifically at those ISIS leaders plotting external attacks.
Following the Paris attacks, the hope is that there will be more intelligence sharing among the European countries so that they can coordinate security checks across their own borders. As one U.S. official put it, there may be a "post-Snowden swing back" on surveillance and what the European public is willing to stomach.
A very big part of the Obama administration's strategy now rests on whether a ceasefire can be brokered in Syria since that war zone is a haven for ISIS. That's why President Obama spent 30 minutes with Russian President Vladimir Putin -- a patron of Syria's embattled President Bashar Assad -- to convince him to abandon Assad and join the fight against ISIS.
Mr. Obama also nudged skeptics like Turkish President Recep Tayyip Erdogan and the Saudi king to get the Syrian rebels to agree to a ceasefire by January 1st. The gamble -- and it is a big one -- is that they can eventually get all the armed militias and the Assad regime to focus on fighting ISIS instead of each other.
On the day after the attack, Secretary of State John Kerry negotiated the outline of this diplomatic deal in Vienna after months of haggling.
Iran's top diplomat signed off but it is unclear whether the hardline Iranian Revolutionary Guards (IRGC) will honor it.
That's not the only uncertainty, however. The negotiations were led by the U.S. and Russia, even though the two countries disagree on the exact timing of Assad's exit.
An even bigger question is what parts of the Syrian opposition will be allowed into the negotiations with the Syrian government. Jordan is taking the lead on that issue.