Damien Cave of the Baghdad Bureau of the New York Times answered questions about life in Iraq. He quoted one of the post's commenters, Joe Millsap, a marine officer who said he spent two tours in [Baghdad?]:
“Ten days of calm can be followed by ten hours of intense violence and chaos,” [Joe] wrote. “It is a surreal experience, one that cannot help but affect your psyche.”
It strikes me that this is the new face of urban warfare. Punishing, highly precise urban strikes with little or no warning, touching off a brief retaliatory exchange or flurry of activity. Followed by stretches of eerie calm and normalcy.