Misti - Read the BBC link.
The protest that began all this were street protests. There were no armed anti-government groups then. They were just people in the street, the teenagers in Deraa were just teenagers writing slogans on a wall.
The Assad regime started firing on the street protesters and tortured and detained the teenagers.
That is how it started. It really is not more complex then that.
What has made it more complex is being allowed to fester for 5 years, allowing Assad's proxy allies to throw their weight around and ISIS to emerge.
There are still large number of opposition forces. Talk of who is "moderate" is a misnomer, moderate to who exactly?
Besides which, after five years of fighting against a dictator, watching your homeland being destroyed, your family and loved ones slaughtered, while the world turns its back on you, how "moderate" would you be?
"but all those arm sales that the UK and other western countries make to the Middle East do not end up in the hands of peaceful democratically elected governments."
None of it was sold to democratically elected governments in the first place. What has that got to do with Syria? The bulk of what we sell abroad are aircraft and associated materials. That certainly has not ended up in Syria.
Drawing false equivalences between Assad and the opposition fighters is used as an excuse to do nothing, but doing nothing isn't working.
The refugee crisis is going to get even bigger and that will impact Europe and ISIS being allowed to fester and grow will have even more of global impact.
Now Russia is involved, which is making everything worse, both on the ground and in terms of international co-operation.