I can see two major (just enormously large) problems in here.

1. None of us can claim (s)he knows the truth.

If you read news articles what western media write about the civil war in Syria, and what Russian media write, you'll get an impression there are two completely different events. Someone has already noted it on this forum as I remember.
According to the formal logic laws, there can not be two true statements which contradict to each other. Someone is lying. Or maybe someone is providing "half-truth" by pulling facts out of contexts and hiding some other facts. This "half-truth" is actually another sort of lie, just because it is aimed on cheating readers. Either US and Europe, or Russia do lie to their people - it is obvious from the logic laws.

But the question is: WHO is lying? My deep feeling is: both sides are. I cannot fully trust any source on that. I cannot trust the US official opinion (thank Snowden! ), and frankly speaking I never felt like trusting it before. But I do not trust the Russian government either. Since there were obvious events when our government lied us (thank Parliament Elections 2012, with 146% for United Russia shown in state TV - I saw it myslef; thank "Время" TV programme which kept silence when the Net was full of pictures of mass protests in Moscow).

So, I think what Russian government tells us about Syria is at least "half-truth" (a sort of lie), but it is no way the real truth.

I think (unfortunately) no one wants to tell their people the truth. There is hardly any single country in the world which does not lie to their citizen and to other countries. It is just the world we all have now. It is a world ruled by personal interests of highest officials. It is a world ruled by big money. It is a world ruled by political ambitions of some specific people. It is not a world for everyone yet...

2. The civil war lasts for 2 (or more?) years already with at least 100,000 died. How many wounded? How many people lost their parents, children, spouses? How many lost their homes and everything they had?

Why no one made an effort to stop it before? I do not think the position "it's their own business, let them manage it" is fair in this case.
The civil war MUST be stopped. But how?

Unfortunately, the modern world is not so good for that (see item 1). And here's the result we see.

If world's governments had not been busy with defending their private interests, they would be able to consolidate their will to stop the war. I think there must be some kind of an international law and permanent international peace-keeping forces.

Imagine: you walk along a street and you see some people scuffling and nearly killing each other. What would you do? Would you just pass them by pretending it is not you business? I hardly think anyone agrees it is a proper behaviour. We should intervene just to separate the fighters, or (if we do not feel confident of our physical force) at least should call the police.

The internation forces should react wherever deadly violence starts and the local government cannot (or does not want to) suppress the violence immediately. Their task is not to prosecute anyone, is not to punish. Their task is to part the combatant parties with a minimum harm to the peaceful population. They must not support any of the combatant parties, neither to judge who is wrong and who is right. After the peace is established, an international trial (including local people) will judge.

I understand it is something that is easy to say and not easy to do. But the world needs a strict, well-defined law for that. All the countries must participate, every country must delegate their representatives to the peace-keeping forces and to the international trial. Every country should have equal vote. Not the governments but experts must decide.

However, it is hardly possible in the world of lie. And it is sad.

I think the humanity will build a world of truth some day. To achieve that, it will have to get rid of the power of money.
"Everyone has a right to be elected" is a huge lie the modern democracies sell to us. Only someone who has a great influence already, or someone who possesses an enormous amount of money (which is almost the same) can be elected now. And having been elected, they do their best to promote their personal interest first of all. That is the source of all the problems we are facing right now in the world.