Syria is a textbook case of a regime using ruthless brutality to maintain itself in power.

I first witnessed it in spring 1982 when, as a young Arabic language student, I was on a bus from Damascus to Aleppo. The usual babble of voices and music fell to sombre silence as we drove through Hama. The previous month, the city centre had been devastated by the Assad regime in its drive to destroy the Muslim Brotherhood. In the weeks that followed, we learnt of mass executions of hundreds of Islamist prisoners at Tadmur prison. The opposition to President Hafez al-Assad was crushed, and the regime wanted ordinary Syrians to know they would go to any lengths to preserve their power. It was a method the regime would use again 30 years later.

When Hafez al-Assad died in 2000, his son Bashar took over and had aspirations for social and economic reform. But political change was never an option: power in the regime was jealously guarded by the minority Alawites who were resented by the majority Sunnis. Hopes of any reform were dashed in the aftermath of the 2003 US invasion of Iraq.

Bashar quickly determined that he could not afford the overthrow of Saddam Hussein to be a success for the Americans. For sure the US occupiers made mistakes; I was in Baghdad at the time and my arguments against wholesale removal of those members of Saddam’s ruling party — de-Baathification — and disbanding the Iraqi Army were ignored. My American colleagues had their marching orders from the Pentagon. But it was the Syrians who armed the Sunni resistance, fed Islamist fighters — yes, the ones they tried to destroy in 1982 — down the Euphrates valley and made life hell for the American forces. Iran, an ally of the Assad regime since 1982 when they worked together to resist the Israelis in Lebanon, came to the same conclusion: the US had to pay a painful price for overthrowing Saddam, as they might be next if it was an easy win. So Iran armed and trained Shia militias to add to the mayhem.

The top priority for Damascus was that Iraq should become a bloodbath so that America would emerge diminished and would never again use force to overthrow a Middle East regime they didn’t like. That gamble by Bashar reaped its reward eight years later. Popular demonstrations in Syria, inspired by the Arab uprising, were crushed. The Syrian opposition moved to armed resistance and then wholesale civil war broke out. But the west never intervened.

Sam Dagher’s book Assad or We Burn the Country is a vivid and at times gruelling account of the suppression of the Syrian resistance. The awkward title comes from graffiti daubed by regime security forces in areas they had wrested control back from the rebels. It is a powerful testimony of a war correspondent for the Wall Street Journal. His account carries the outrage and passion of a witness to atrocity.

Dagher tells his story in part through the eyes of moderate educated Syrians who opposed Bashar. They were the ones most ruthlessly targeted by the Bashar regime and its Russian and Iranian allies. The moderates had to be destroyed first as they blurred the dividing line that Bashar wanted to create between the regime as the source of legitimacy and stability, and the opposition as terrorists.

A failing common to those in intelligence, diplomacy and journalism is that they inflate the importance of information from their personal contacts. One of Dagher’s main sources is Manaf Tlass, the privileged son of Hafez al-Assad’s long-serving Sunni defence minister who, together with a succession of foreign ministers, was a public face of the regime aimed at disguising its sectarian nature.

In London, we watched Tlass through 2011 and early 2012 as he distanced himself from Bashar and then defected. Was he an alternative to Bashar? He proved a disappointment. His priority was to save his own skin. He never had the bottle for leadership, and his family’s role in regime brutality meant he was anyway unacceptable to the rebels.

Tlass’s story is an interesting one, which Dagher tells well. But some of Tlass’s account is questionable. For example, his assertion (taken as fact by Dagher) that Bashar had his own brother-in-law, Assef Shawkat, killed as he risked becoming an alternative figure of power, has never been substantiated.

Military intervention is a challenge for liberals. The invasion of Iraq was roundly condemned — more so in hindsight than at the time. The Anglo-French initiated Libya operation of 2011 was criticised as inadequate as it did nothing to restore order after Gaddafi was killed. On Syria, western liberals implored the Obama administration and the Europeans to do more to prevent the humanitarian catastrophe that Bashar had created. But as the Syrian leader had calculated, the bloody experience of Iraq meant there was no appetite for another military intervention. In the end, the west and its allies in Turkey, Jordan and the Gulf provided enough support for the rebels to keep the war going but not enough to be decisive.

Baghdad, 1978: Iraqi leaders Saddam Hussein, left, and Ahmed Hassan al-Bakr meet with Syrian president Hafez al-Assad, right © Getty

The failure of David Cameron, then UK prime minister, and President Obama to respond after the 2013 chemical weapons attacks near Damascus when the regime was at its most vulnerable sealed the rebels’ fate. Cameron was the first to duck the decision, opting to refer it to parliament, and it unravelled from there. The field was left open to Russia and Iran, who duly mopped up the Syrian opposition, leaving the west to focus on Isis and al-Qaeda, terrorist groups that Russian president Vladimir Putin was quite happy to see dismantled. The Israelis who, at first, had wanted to see the Assad regime ousted switched to backing Damascus as they were the lesser evil compared with the Sunni extremists. Turkey too adapted to the new reality of Russian and Iranian power and the west in retreat.

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Dagher’s engrossing account focuses on events in Syria itself, but he is clear that the west let down those Syrians who resisted the regime’s violence and wanted change. The lessons for policymakers come through powerfully. Invading Iraq was a strategic mistake, but at least, 15 years later, we have a vastly better Iraq. Dagher shows that the west’s policy failure in Syria was at least as bad, and there is nothing to show for it beyond half a million dead, half the population driven from their homes, and Bashar’s sectarian regime still in power in a now devastated country.

Second-generation dictators such as Bashar usually lack the guile and manipulative skills of those who had to win power in the first place, so they depend all the more on violence. A life of wealth and privilege is poor preparation for the challenges of leadership. Bashar will hope that his display of ruthless violence on his own people will make them acquiesce to his rule for the coming decades, as his father’s brutality in Hama did. Sadly, ordinary Syrians have little alternative.

Assad or We Burn the Country. How One Family’s Lust for Power Destroyed Syria, by Sam Dagher, Little Brown, RRP$18.99, 592 pages

John Sawers is executive chairman of Newbridge Advisory and a former chief of MI6, the British Secret Intelligence Service

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