Though violence in Iraq has declined, withdrawing US troops too quickly would spell failure in some parts of the capital, a top general said Monday. Maj.-Gen. Joseph Fil, commander in Baghdad, said progress made toward securing the city in recent months is "fledgling, fragile and not guaranteed." He said that although violence is diminished, it has dropped because the troop buildup ordered by President George W. Bush in January has made it possible to have a "force presence that is almost throughout the city," comprising U.S. and Iraqi forces, supplemented by so-called "Concerned Local Citizens" groups. Attacks in Iraq are at their lowest levels since the first year of the US-led invasion in 2003, finally opening a window for reconciliation among rival sects, Lt.-Gen. Ray Odierno, the No. 2 commander in Iraq, said Sunday.