- Obama will meet with the Turkish and Russian presidents at the G20 on Sunday
- Aaron David Miller: Given the issues that divide them, Obama should keep expectations low
Aaron David Miller is a vice president and distinguished scholar at the Woodrow Wilson International Center for Scholars and author of "The End of Greatness: Why America Can't Have (and Doesn't Want) Another Great President." Miller was a Middle East negotiator in Democratic and Republican administrations. Follow him on Twitter @aarondmiller2. The opinions expressed in this commentary are his.
(CNN)Behind the forced smiles and obligatory handshakes that mark what could be President Barack Obama's final encounters with Recep Tayyip Erdogan and Vladimir Putin this Sunday at the G20 lurks one undeniably inconvenient reality: These days, more divides Russia and Turkey from the United States than unites them.