In August 2012, the American journalist Chuck Todd, enquiring into Barack Obama's "latest thinking" on the rebellion in Syria, which at the time was a year old, asked the now former president if he ever envisioned intervening militarily in Syria to ensure "the safe keeping of the chemical weapons" in Syrian president Bashar Al Assad's arsenal. According to the Federation of American Scientists, Syria under the Al Assads had built up "one of the largest and most sophisticated chemical weapons programmes in the world". Mr Obama answered the question with uncharacteristic unambiguity: "We have been very clear to the Assad regime", the president said, "that a red line for us is … chemical weapons moving around or being utilised".
Mr Al Assad did not wait long to start testing president Obama's red line. On December 23, he dropped bombs containing a toxic gas called Agent 15 on Syrians queuing for bread in the city of Homs. The White House not only did not take action, but it also issued a statement saying that reports of chemical weapons use were not "consistent" with its own assessments. Mr Obama's failure to enforce his own warning clearly emboldened the Syrian regime. On August 21, 2013, four years ago today, Mr Al Assad rained bombs loaded with sarin gas on Syrian citizens outside Damascus. The images of suffering that emerged that day from Ghouta will long haunt humanity. They are a stain on our conscience.
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Even though the red line had been crossed, Mr Obama feared that intervention in Syria might turn it into another Iraq. This was the wrong lesson to draw from history. As events have shown, his refusal to punish the Syrian president has meant that, four years on from the massacre in Ghouta, Mr Al Assad has consolidated his position. The insidious narrative that Iran, Russia and Mr Al Assad are fighting terrorism, when if anything they are at the forefront of terrorising and killing Syrians, has taken hold. And Mr Al Assad is now treated as integral to any solution to the crisis in Syria, rather than as the person who precipitated the conflict. The Syrian president again used chemical weapons in April this year, killing dozens of people in Idlib. While the crossing of that red line once more was enough to stir the new US president, Donald Trump, to order a retaliatory cruise missile attack on Shayrat air base, the action appeared more symbolic than strategic. It was designed to prevent and deter the Syrian regime from launching future chemical attacks, but in reality served only as a light slap on the wrist to Mr Al Assad.
No atrocity, it seems, can shock the world into acting against Mr Al Assad. As Carla Del Ponte, the Swiss lawyer who earlier this month resigned from the UN Commission of Inquiry on Syria in protest at the Security Council's unwillingness to hold Mr Al Assad to account, said: "there is no justice for Syria". Few truer and more realistic assessments exist of this years-long conflict.