Today marks a significant turning point in the Syrian Civil War (2011-present) because the USA will now officially supply armaments to the rebels fighting Syria's Bashar Hafez al-Assad-led government forces.
Above is an ethnoreligious map courtesy of Wiki Commons (from 2012).
To compare scale, Syria has many more people involved than did the American Civil War of 1861-1865, in which more than 600,000 died. Syria's population (including refugees) is about 23 million strong; so far, probably more than 100,000 people have died in its current civil war (about 93,000 is the official UN estimate as of today, mostly civilians).
A closer equivalent might be the Spanish Civil War (1936-1939) -- Spain had a population of about 24-25 million people at the time. An estimated 500,000 died in the course of that internecine war; I'm not sure if the total number includes 150,000 or so executed by the government of Generalissimo Francisco Franco in its wake, or if the total rises to 650,000.
As with Spain, so now with Syria also in the sense of drawing in other nations, volunteers, weapons and additional supplies.
The Spanish Civil War is often depicted as a technological testing ground and precursor to World War II. The Syrian Civil War may be seen within the larger context of the "Arab Spring;" as for other effects, they will unfold with time.
Today's Rune: Strength.