BAGHDAD, Iraq - Kurdish parties warned Wednesday that they might bolt Iraq's new government if Shiites gain too much power. In another challenge to the interim administration, saboteurs blew up an oil pipeline, forcing a 10 percent cut in electricity output. Kurdish fears of Shiite domination rose after the Americans and British turned down their request to have a reference to the interim constitution — which enshrines Kurdish federalism — included in the U.N. resolution approved Tuesday. The country's most prominent Shiite leader, Grand Ayatollah Ali al-Husseini al-Sistani, warned he would not accept mention of the interim charter in the...