To start a fire you need a flame source, tender, and the right fuel. The assassination of Arch Duke Ferdinand was the flame source only because relatively minor players under the Kaiser wanted it to be. By controlling what information the Kaiser saw and changing or not delivering his instructions it was minor functionaries behind the scenes that made the fire start.
The disturbing parallel here is the incompetent people around our president coupled with his incompetence and magical thinking that may lead us to an armed confrontation with a nuclear superpower. Apparently our ambassador to the Ukraine was in the streets meeting with revolutionaries. Imagine if Russia’s ambassador openly supported the Occupy crowd and suddenly the Occupy crowd had man pads and millions of dollars. We would automatically assume that Russia supplied the money and the weapons. If the ambassador really did that then the ambassador should be brought back to face charges. An ambassador represents the United States and, from a political perspective IS the United States. Although the US might support protesters politically in the US they should never actively meet with dissidents of a “friendly” power on that power’s own soil. An ambassador gathers information about the situation and reports. Anything else exposes the country they represent to retaliation.