The aftermath of the Ghouta CW massacre is highly instructive. The attack was the most clear violation of Obama's "red line" on the use of chemical weapons in Syria & the regime expected it will be bombed. Regime officers moved into civilian hotels in Tartous to avoid being hit.

Russia sprang into action & convinced the regime to give up its CW in exchange for avoiding American strikes. The regime, which until that point was claiming to not possess any CW, gave up most of its Sarin stockpiles under OPCW supervision.

Assad continued smaller-scale chlorine gas attacks & after facing 0 consequences for them under Obama, resumed Sarin gas attacks. But giving up most of the stockpile is a rare concession made by the regime that has insisted on its right to slaughter its population how it sees fit

The US admin currently possesses way less leverage than it did in 2013, but one truth remains: the regime and its allies respond to credible threat of force. This can be observed in all the instances when such a threat or actual use of force were used:

1) In 2018, a group of Russian mercenaries, foreign Shia militiamen, Syrian soldiers & militiamen launched an attack on the Conoco gas fields under SDF control & US protection. US forces opened fire, between 55-200+ pro-regime fighters were killed.

The Syrian regime is broke, in desperate need of the oil, gas & wheat under SDF control, yet it has not dared to mobilize its troops against the SDF again & it won't retake these areas, unless the US withdraws it protection.

2) Israel has been bombing targets in Syria for years. Ardent Assadists want to retaliate in kind: if Israel bombs Damascus, the regime should be bombing major Israeli cities. Until a few years ago, the regime didn't even dare to activate air defense systems against these attacks

3) The Turkish intervention in n Aleppo starting 2016 was met with regime condemnation, yet in never mobilized troops against these territories or bombed them.
4) The Turkish intervention in Idlib is particularly instructive about the importance of *credible* threat of violence

Turkey first inserted troops into Idlib, with Russian & Iranian acquiescence, in 2017. Yet those hundreds of troops, based in observations posts throughout Idlib, were unable to prevent regime offensives on Idlib. In 2020, regime forces w/ Russian supported gained ground rapidly.

1 million Syrians fled their homes toward the locked Turkish border. Turkey repeatedly issued warnings that it'll mobilize forces if offensive doesn't stop (fearing mass influx of refugees), yet the regime & allies pressed on. Turkey began bringing in 1000s of soldiers into Idlib

Russia, the regime & Iran still thought Turkey was not serious about it threats (Lavrov said so explicitly in a private meeting w/ Western officials in mid-Feb 2020). As rebel defensive lines crumbled, Turkey mobilized into action: its UAVs & artillery began hitting regime forces

It took a little over a week of Turkish strikes, which killed hundreds of Syrian soldiers & destroyed dozens of Russian-manufactured armor, artillery & air defense pieces (notably the expensive Pantsir system), for the Russians to understand Turkey is no longer bluffing.

Russia accepted a deal much worse than the one it originally proposed (a tiny stretch of land along the border). Russian officials now admit in private they miscalculated to what an extent Turkey was determined not to see any more territory lost due to fear of refugee influx.

The ceasefire in Idlib is shaky, but has been holding for almost 6mo. I expect it to continue to hold because for the 1st time, they regime & allies are faced with a credible threat of force. Since March Turkey injected even more troops into Idlib & brought in air defense systems

Assad hasn't altered his behavior through diplomacy or due to economic pressure. Russia may be moved by sanctions, but its leverage over Assad on issues unrelated to military operations is incredibly limited.

For liberals, the realization that with some regimes, only the threat of force works is a troubling one. Yet in Syria, not using this card, means allowing a criminal, broke & corrupt regime to remain in power, producing future instability & preventing refugee return.

The US still has leverage in Syria, if it is willing to use it. Even with the current leverage & level of military involvement, it can at least prevent additional areas & their millions of inhabitants from falling under regime control & becoming its future victims.