The basic reason that the United States is fundamentally wrong (gravely criminal) in Syria, and Russia is fundamentally right (morally just, and lawful), is this:
The United States, for 6 years, has armed and paid for an invasion army composed of foreign non-Syrian mercenaries loyal to ISIS and Al Qaeda. ISIS and Al Qaeda are America’s army, paid and armed (including chemical weapons) by America, carrying out America’s war of aggression against Syria, a war aimed at overthrowing the government of Syria. This is gravely criminal. (Full Stop)
Syria is defending itself from foreign invasion, and so by definition alone, and for other reasons that are obvious, Syria, it’s government, it’s army, the Syrian Arab Army, and it’s President, are fundamentally right, morally just and lawful.
The same goes for Russia. Russia is Syria’s ally and is helping Syria, at Syria’s request, and with the tremendous gratitude of the Syrian people, defend Syria from foreign invasion by America’s proxy army, ISIS and Al Qaeda.
But what about a comparison of the quality of life, comparing the freedom and justice within Syrian society to the quality of life according to ISIS and Al Qaeda. Here again, one comes to the same conclusion: Syria and Russia are fundamentally right, morally just, and lawful while the United States and ISIS and Al Qaeda are gravely and morally criminal.
The United States is trying to destroy, the Syrian women in this video https://youtu.be/EhL8D0wYevo. Take a look at it, 18 minutes of interviews with people in Syria. These are the people, and this is the society, that the US is trying to destroy, and replace with a fundamentalist jihadist medievalism by arming and paying a terrorist invasion proxy army composed of ISIS and Al Qaeda and variants.
Links to more information about Syria here: https://dagsljus.wordpress.com/2017/01/22/syria/
Remarks on geo-strategy, by Mike Whitney: http://www.counterpunch.org/2017/04/07/the-impending-clash-between-the-u-s-and-russia/