Fawaz Gerges, Director of the Middle East Center at the London School of Economics, has told ITV Daybreak that "it would take a spark to ignite the conflict in Syria."
He added: "The conflict in Syria has mutated and taken a very dangerous turn. It has major implications for regional stability and international peace and security."
More top news
The boy was attacked on a bus in south London. Police say he was stabbed in the stomach.
With Donald Trump and Hillary Clinton looking set to become the Republican and Democrat presidential candidates, what happens next?
Everything you need to know about the most violent day of the miners' strike.