The forces of Bashar al-Assad, the president of Syria, have been killing Syrians mercilessly for 13 months while the world has fumbled for a credible strategy to remove him from office. The rhetoric has been strong: he must go; this is his last chance; his loss of legitimacy is irrevocable. Such phrases have been heard time and again over the past year.

But the Syrian dictator hangs on, his supporters now predicting, and his enemies fearing, that he could be in power for years. He is undeterred by increasing isolation and by the sanctions piling up against his cronies, even though these have frozen Syria’s oil exports and crippled its economy.

His friends in Russia (a source of diplomatic backing) and Iran (a source of funding, military advice and possibly also weaponry) remain committed to his survival. His international opponents know that Syria’s crisis is not only a humanitarian tragedy: the fall of Mr Assad would bring significant strategic gains to the US and Europe, altering the balance of power in the Middle East by removing Iran’s most Arab ally. Yet, while western governments float ideas like setting up humanitarian corridors and safe havens, they quickly roll back, unable to bring Russia on board and, in any case, lacking the political will for Libya-style military involvement.