US officials say that President Obama is close to shifting his stance on shipments of anti-aircraft weapons to Syrian rebels, amid growing Saudi pressure to allow such shipments.

Such shipments have been hugely controversial, as many of the rebel factions are overtly linked to al-Qaeda, and even those who are not have openly talked about using the missiles against civilian airliners.

Saudi Arabia has been hoping to send the missiles for years, and recently pushed the idea again as a way to blunt the Syrian Air Force impact on the seemingly endless civil war.

While the missiles could indeed change the complexion of the war, and force Syria to rely less on air power in fights against northern rebels, the destruction of commercial airline flights in the area is likely to be a major source of embarrassment for both the Saudis and the US.