Much of the present trouble between Sunnis and Shiites has to do with ancient history. The Sunni Arabs invaded, defeated, brutally ruled the Persian Empire in the 7th Century until the Persians were able to throw off the yolk of Arab rule several centuries later, but not b4 converting much of the Persians (including the Zorat, Jews, Christians, Hindus and Buddists, etc.) to Islam. However, the Persians wanted to distinguish themselves from much of the Arabs populations by following a different stream of Islam than that followed but Sunni tribes.
Condition of woman seriously wounded in Jerusalem stabbing attack slightly improves (Haaretz)
from the article: The victory won't be American