Bashar al-Assad has normalised the use of chemical weapons in Syria – and we rewarded him for it

This week, the Organisation for the Prohibition of Chemical Weapons (OPCW) confirmed what everyone already suspected: the Syrian regime of Bashar al-Assad had lied repeatedly about its adherence to a deal worked out in 2013, under which it would surrender its chemical weapons of mass destruction (CWMD).

The Syrian uprising began in March 2011 with peaceful protests. By the end of the year, the Assad regime's unrestrained brutality – which saw the murder of 5,000 people – provoked a militarised response as the population took up arms to defend itself.

Throughout 2012 the Assad regime escalated its response: artillery levelled sections of ancient cities like Homs, helicopter gunships were employed, fighter jets bombed urban centres, and Scud missiles – designed for inter-state warfare – were deployed internally, against civilians.

This strategy of collective punishment and mass-displacement as a means to suppress the uprising culminated with the Assad regime unleashing chemical weapons against civilians, probably first doing so in December 2012.

President Obama said in August 2012: "A red line for us is we start seeing a whole bunch of chemical weapons moving around or being utilised. That would change my calculus." In December 2012, Obama reiterated the threat, saying the use of CWMD would bring "consequences".

But Assad repeatedly used nerve agents and other CWMD over the next six months, without consequence. In June 2013, the US publicly stated that Assad had used CWMD and the "consequence" would be the first provision of "military support" to the rebellion. But this lethal aid only started arriving in September 2013—after a massive CWMD attack.

On 21 August 2013, the Assad regime used sarin nerve agent to massacre more than 1,400 people in the Damascus suburbs of Ghouta. President Obama was set to launch a round of airstrikes – the French had prepared jets to join the attack—against Assad's military and unconventional weapons sites when the matter was halted, put to a vote in Congress, and then abandoned completely for a "deal" with Russia, which in the administration's telling meant Assad surrendered the CWMD he had heretofore denied possessing in exchange for the strikes being called off.

The reality was rather different. Obama had never intended to enforce his "red line" – it was a bluff that got called. Additionally, Obama had begun secret talks with Iran on the nuclear deal and from late 2012 Tehran had effectively taken control in regime-held areas of Syria. A conflict with Iran in Syria might derail the President's legacy project.

The president's signalling, therefore, was not that he would use force unless Assad gave up his CWMD: the stated aim was to punish Assad and uphold an international norm. The signal instead was that the President would take any available option to avoid doing what he did not want to, and Moscow providing the decommissioning of Assad's stockpiles as a fig leaf.

Assad was made a partner in disarmament, extending him some legitimacy, as the Russians had wanted. The West was made complicit in campaigns of atrocity that were passed off as the regime "taking steps to secure" the exit routes for the CWMD, and Assad was, despite all reassurances to the contrary, handed "a license to kill with conventional weapons". The effect on the moderate and Western-supported rebels was "devastating," and radicalism on all sides was given a boost.

For this extreme price, Assad was not even disarmed of his CWMD – a sideshow in terms of what was inflicting the casualties. In June 2014, all declared CWMD was removed. This was, said President Obama, a demonstration that "the use of these abhorrent weapons has consequences".

That October, OPCW found four secret CWMD facilities, one of them a production site. By summer 2015 it was clear in open-source that Assad had retained some CWMD, and US intelligence confirmed this in early 2016. Meanwhile, Assad began the routine use of alternate chemical weapons against Syrians, notably chlorine. A separate, simultaneous OPCW investigation has documented eight of these atrocities by the regime.

But without an alteration in the balance-of-power on the ground in favour of the mainstream armed opposition, the terms of the discussion will remain the regime's whenever the next round takes place

There have been no consequence for Assad trading sarin for chlorine – nor for the barrel bombs, incendiary weapons, starvation sieges, airstrikes, and use of death squads that have destroyed a country and ignited a region-wide war that has killed half-a-million people.

When asked about his decision to stand back from military strikes against Assad in 2013, President Obama said he was "very proud of this moment". The US has all-but abandoned the stated regime-change policy, and is instead inching ever-closer to an accommodation that keeps Assad in place. The Russians managed, via their intervention, to turn the peace process inside-out: from a means of transitioning Assad out to a discussion about the terms on which he could stay.

That process was jointly killed earlier this year by Assad and al-Qaeda making the ceasefire untenable. But without an alteration in the balance-of-power on the ground in favour of the mainstream armed opposition, the terms of the discussion will remain the regime's whenever the next round takes place.

The failure to punish Assad at the time for the Ghouta chemical massacre has done irreparable harm to one of the few international norms left, contributed beyond calculation to the radicalisation of Syria and the rise of anti-Western sentiments, and the course of events since has underlined the lesson that such criminality pays. It is now widely agreed – even by parts of the Turkish government, probably the most hawkishly anti-Assad – that Assad will to have some role in a "transition". The contrast to the autocrats who were not prepared to kill on this scale and thus fell from power is stark.

It can also be guaranteed that just as Assad strung out the disarmament process so that he was always necessary – eternally disarming and never quite disarmed – any transition in Syria overseen by the dictator will be one in which Assad is always going and never actually gone.

Kyle W Orton is associate fellow at the Henry Jackson Society and a Middle East analyst and commentator. Follow him on Twitter @KyleWOrton