Why was the First Temple destroyed? Because of three sins: idolatry, immorality and bloodshed. But why was the Second Temple destroyed, seeing that during the time it stood people occupied themselves with Torah, with observance of mitzvot ("commandments"), and with the practice of tzedakah ("charity")? Because during the time the Second Temple stood, sinat hinam ("baseless hatred") prevailed. This teaches us that baseless hatred is deemed as grave as the sins of idolatry, immorality and bloodshed combined.
--Talmud (Yoma 9b)
Dave at Israelly Cool has some apt observations about one modern variation of such baseless hatred. He's also got more on the observance of Tisha B'av, which starts tonight, and a connection to a certain infamous date in recent American history. (And Dave -- I've never been so sure it's a coincidence.)
To all who are observing the fast, may it be an easy one.
