NEW YORK (AP) — U. S. stocks and oil prices flip-flopped as uncertainty rose about what will happen following a two-week ceasefire in the war with Iran, which is set to expire Wednesday. The S&P 500 erased an early rise and fell 0. 6% Tuesday after Vice President JD Vance called off a trip to Pakistan, where he was expected to lead U. S. negotiators in talks with Iran to extend the ceasefire. The Dow Jones Industrial Average fell 293 points, after erasing an earlier rise of 400 points, and 0...