Where is the Syria strategy?

 Trudy Rubin:

 'When the White House announced Monday that Syria might be preparing another poison gas attack - and warned of dire consequences - critics were wary.

 Some saw the warning as a "wag the dog" feint to distract from the Senate failure to move on repealing Obamacare. After all, President Trump didn't seem to take the gas threat seriously, ignoring it in his tweets in favor of more denunciations of the Russia probe.

 Others saw the warning as a pure pretext for sending thousands of U.S. ground troops to Syria in the near future.

 That skepticism was misplaced. It was necessary to warn the Assad regime off any further use of chemical weapons in order to avoid a massive U.S. military retaliation.

 But there is room for skepticism about the administration's wider Syria policy, or lack thereof, beyond aiding in the destruction of ISIS headquarters in Raqqa. Without a clear plan for what comes after the fall of Raqqa, the United States could get drawn deeper into the Syrian civil war.

 First to the gas threat. The White House warning was triggered by suspicious activity observed at the Shayrat air base from which the Assad regime launched a sarin attack in April. The Trump administration launched missiles at the base on April 7, as punishment for this violation of the international ban on use of chemical weapons.

 The Trump team sought to draw a sharp contrast with the Obama White House, which had backed off a pledge to strike Syria in response to a much larger gas attack in 2013. President Barack Obama chose instead to make a deal with the Russians to guarantee the destruction of Syria's store of chemical weapons. Clearly, the Syrian regime has kept some of its nerve gas stocks, which the Russians must be aware of.

 Had Syrian president Bashar al Assad flaunted the international ban on poison gas once more, proving he retains WMD, the administration would have been in an extremely difficult position. Having taken action once, the pressure would have been intense to carry out more severe air strikes.

 But the Russians deny that their Syrian ally still has poison gas, just as they continue to deny (despite clear evidence) that Assad carried out the 2013 sarin attack that killed 1,000 civilians. A major strike could have led to a clash with Moscow, which is giving Assad heavy air support at a time when U.S. aircraft are also flying over parts of Syria.

 Yet not to respond, would have given Assad the green light to keep on using nerve agents, while denying to the world he had any. Since the Syrian leader is short of troops, gas is the perfect weapon to send terrorized civilians fleeing from the rebel-held province of Idlib into Turkey, which could in turn set off another refugee flood to Europe.

 Far better to issue a public warning now, to let Moscow know it had better restrain its client or else the White House would have no choice but to retaliate.

 However, contrary to White House claims, the April missile barrage on Shayrat (which I believe was necessary) did not prove to Assad, or his Russian and Iranian backers, that Trump was a tough guy. It was a tactical move that changed little.

 Russian planes and Iranian-led militias have been busy helping Assad wipe out any opposition, while leaving the dirty work of fighting ISIS in the Raqqa region to Kurdish forces backed by U.S. pilots and special forces. As the battle for Raqqa ramps up, there appears to be no wider U.S. strategy for what to do after this caliphate capital falls.

 But that leaves many critical political questions unanswered. One big one: Does the United States care if the territory south and southeast of Raqqa, up to the Iraqi border, is controlled by Tehran? Iran wants to solidify a land bridge that runs through Iraq and Syria, and ultimately reaches Lebanon, so Tehran can easily funnel heavy weapons and men to its anti-Israel ally Hezbollah.

 Some Trump advisers reportedly want to insert thousands of U.S. troops into Syria to block Iran's intentions. But the U.S. military and Secretary of Defense James Mattis vehemently oppose the idea. "We just refuse to get drawn into the Syrian civil war," Mattis said this week. "We try to end that through diplomatic means."

 Smart man. But right now the U.S. military strategy in Syria is like a headless horseman, plunging ahead without any broader political framework.

 Trump will meet Russian president Vladimir Putin at a G-20 summit in Hamburg in early July, and Syria is a subject they should be discussing. But those talks can't bear fruit unless Trump understands that Russia's interests in Syria differ profoundly from ours.

 America needs a stable Syria so that a new jihadi menace doesn't take root. But Putin's main concern is keeping Assad in power with Iran's help, even if that means continued repression that will fuel a future jihad.'