CHARLESTON, W.Va. — Senator Barack Obama on Thursday blamed the fragile economy on “careless and incompetent execution” of the Iraq war, imploring voters in this swing state to consider the trickle-down economic consequences of the war as they choose a successor to President Bush. “When you’re spending over $50 to fill up your car because the price of oil is four times what it was before Iraq, you’re paying a price for this war,” Mr. Obama said to an audience at the University of Charleston. “When Iraq is costing each household about $100 a month, you’re paying a price for...