The Iranian- and Russian-backed regime of dictator Bashar al-Assad has used banned chemical weapons against its own people more than 300 times since former President Barack Obama declared in 2012 that such attacks would cross a “red line” that would trigger a U.S. military response, the Germany-based Global Public Policy Institute (GPPI) reported on Sunday.

In August 2012, then-President Obama declared that Assad’s use of chemical weapons was a “red line” that the regime should not cross. Instead of enforcing his “red line” warning, the Obama administration decided to reach a deal that mainly revolved around Russia overseeing the dismantling and destruction of his ally Assad’s chemical weapons stockpile.

GGPI noted in its new study unveiled on Sunday that there have been no confirmed uses of chemical weapons at the hands of Assad since U.S. President Donald Trump ordered retaliatory air strikes against the Syrian regime in April 2018, suggesting that the American military operation had a real impact on what the study refers to as the dictator’s “chemical weapons diplomacy.”

The study explained:

In building this dataset, we collected and reviewed 498 discrete reports of chemical weapons use in Syria from a wide range of closed and open sources. The first credible reported incident occurred on 23 December 2012, and the most recent one on 7 April 2018. As of 18 January 2019, we were able to assess 336 incidents as either “credibly substantiated,” “confirmed,” or “comprehensively confirmed.” We dismissed 162 reports.

GGPI acknowledged that while the Assad regime is responsible for the vast majority of chemical weapons attacks, the Islamic State (ISIS/ISIL) jihadist group has also used the same tactic.

The study revealed:

Our research found that there have been at least 336 chemical weapons attacks over the course of the Syrian civil war – significantly more than has commonly been known. Around 98 percent [329] of these attacks can be attributed to the Assad regime, with the Islamic State group responsible for the rest [7]. Approximately 90 percent [about 302] of all confirmed attacks occurred after the infamous “red line” incident of August [2012].

The study acknowledged that Assad continued to use chemical weapons without facing any repercussions, adding that the dictator is on the brink of defeating his enemies mainly due to his regime’s use of chemical weapons.

GPPI noted:

We show that the Assad regime did not merely “get away” with its use of these banned weapons, but succeeded in using them for strategic ends. More than two-thirds of Syria’s population are internally or externally displaced, and opposition-held communities have been buckling and surrendering under the cumulative weight – and eventually the mere threat – of violence, including the use of chemical weapons.

The Assad regime now controls more territory than any other warring party in Syria, including the U.S.-backed Syrian Kurds. Support from Iran and Russia has also allowed dictator Assad to remain in power.

GPPI urged the United States and the international community to “directly target the military formations that would be responsible for any future attacks” — namely the Syrian helicopter fleet used to drop the chemical weapons.

“Putting a stop to the Syrian regime’s strategy of chemical weapons use will require halting its overall machinery of indiscriminate violence,” the study added.

The Syrian civil war has been raging since March 2011. Late last year, President Trump announced plans to pull U.S. troops out of Syria, stressing that the American forces who will remain in neighboring Iraq will be able to go into the country if necessary.