Even by the grim standards of the 11-month-old Syrian uprising, the killing of more than 200 civilians in Homs in a barrage of artillery fire before dawn yesterday was a horrific act of mass murder. For Syrian President Bashar Al Assad, this is the moment of truth: even if he somehow manages to survive the present upheaval, what kind of country does he hope to rule?

Too much has happened in the past 11 months; things will never be the same again. If he is really as committed to his country as he claims to be, Al Assad must now make a decision — he should accept the Arab League plan calling for him to cede power, leading to the establishment of a government of national unity within two months.

Failure to do so may eventually lead to civil war with proxy, if not direct, foreign intervention. This will further destabilise the region and fuel sectarianism.

While the delusional Syrian regime has dismissed the reports of the Homs bloodbath as a "hysterical campaign" of incitement by armed groups, angry Syrians and their supporters around the world have been storming Syrian diplomatic missions in protest.

Far from tipping the balance in the regime's favour, this unreserved use of violence will only serve to harden the resolve of protesters who have been braving bullets and torture day after day, week after week, month after month to voice their opposition to the regime.

The regime is banking on the support of its powerful allies — Russia and Iran — to survive. But Al Assad must realise that the only realistic way out of the crisis involves him stepping aside. That is the advice Russian Foreign Minister Sergei Lavrov must be giving his friend when he meets him in Damascus on Tuesday.