The bomb attack on the holy city of Najaf in Iraq dealt a new blow to US hopes of bringing stability to the country as well as killing a key moderating influence on the Iraqi Shiite community, US experts said. Ayatollah Mohammad Baqer al-Hakim, a leading Shiiite Muslim cleric, was among at least 82 people killed in the car bomb set off outside the Tomb of Ali, one of the Islamic world's most important shrines. Coming barely 10 days after the truck bomb that killed 23 people at the UN offices in Baghdad, including the UN special envoy Sergio Vieira...