In today's story by the BBC covering Syria they note the the conflict has now officially evolved in to a civil war - http://www.bbc.co.uk/news/world-middle-east-18849362
By being legally categorized as a civil war all participants are now subject to the articles of war - such as the Geneva convention. It also means that the persons behind any crimes and atrocities committed during this war can be prosecuted as international war criminals even after the conflict ends.
With the trials currently underway in the Hague against the leaders of the Bosnia war, I was thinking how different prosecutions of war crime in Syria will likely be different - given a considerably more networked world and advances in electronic monitoring.
When I read about the most recent murders of 100 souls, it is inevitable that there will be a kind of electronic trail that did not exist for wars of even a decade ago.
The instructions and target coordinates of the artillery will have been communicated and authorized electronically - not just as written communications, but also as digital voice and CB radio. The point though is that there will be a recoverable record somewhere. Given the high level of electronic eavesdropping by the combatants and other observers (e.g. NATO forces and local non-combatants), even those localized communications between regional commands and tank drivers can be intercepted, stored, and shuttled to appropriate authorities relatively easily.
Those issuing criminal commands can expect to not only be held accountable, but can expect those crimes and attribution to be documented to an excruciating level of detail - leaving little ambiguity to future courts.
Some may argue that encryption will be their savior. I doubt it. The tools they're using to generate and decipher those communications will become available to investigators post-conflict. And, regardless of access, as we're observing with the prosecutions relating to a conflict that occurred practically two decades ago, technology advances. How sure would you be that even your 128bit encrypted digital radio messages will hold up to decryption techniques and capabilities in 20 years?
No, leaders and those issuing commands will be held accountable with evidence that has never been so rich and attributable.