The future of Syria will no doubt figure in talks today between Donald Trump and Vladimir Putin. So long as the former does not promise a complete and immediate withdrawal of U.S. troops, the main question is whether American forces should remain in Syria after mopping-up operations against Islamic State and, if they do remain, what goals they should pursue. Katherine Bauer, Soner Cagaptay, Patrick Clawson, Michael Eisenstadt, James F. Jeffrey, Barbara Leaf, Matthew Levitt, Dennis Ross, and Robert Satloff lay out the case for an activist policy to counter Iran in Syria with the aid of Israel. They write:
Sanctions and a no-fly/no-drive zone in northeast Syria would prevent Assad-regime and Iranian forces from charging in, which would infuriate local Sunnis and spur the regeneration of Islamic State (IS). Such a zone, coupled with sanctions, would impose costs on the Assad regime by denying it the money and income needed to ensure control and to maintain the patronage networks that underpin its power. This would in turn create financial burdens for Iran and Russia in their effort to keep Bashar al-Assad afloat, just as Tehran’s ability to pay for such support will be diminished by the U.S. policy of maximum pressure. . . .
In terms of Iran, [however,] the Trump administration’s preferred approach of imposing severe economic sanctions will not in itself be sufficient to compel Tehran to change course on Syria or the region. If the administration is seriously committed to the twelve objectives outlined in Secretary of State Mike Pompeo’s May 21 address, countering Iran in Syria is essential. . . .
Moscow has maintained a partnership with Tehran for years built on common antipathy to the United States and fear of Sunni extremism, but it does not necessarily share all of Iran’s goals regarding Syria and Israel. The United States has had little success exploiting that divergence because Russia and Iran share the important common objective of shrinking U.S. influence in the area. Russia wants the United States to accept it as a great power, so Moscow has been eager for talks with Washington about Syria’s future. But this does not mean Russia has the will or ability to do anything that actually restrains Iran. . . .
The actor best positioned to drive a wedge between Iran and Russia is Israel, because it can confront the Russians with a choice they do not want to make: either rein in Iran’s aggressive stance or face the imposition of costs on Assad for his deference to Iran—or, in extremis, a war between Israel on the one hand and Iran and Hizballah on the other. . . . The United States should make clear to Israel, and Russia, that it has no objections to an active Israeli policy of preventing Iran from establishing a permanent military presence in Syria.