LONDON (AP) — Prime Minister David Cameron insisted Monday that Britain's vote to leave the European Union won't send the economy into a tailspin, even as Standard & Poor's stripped the U.K. of its top credit rating. Hours after he spoke, Standard & Poor's knocked the U.K.'s sovereign rating by two notches, from AAA to AA, saying an exit will lead to a "less predictable, stable and effective policy framework in the U.K." The Brexit vote "is just one chapter in a much bigger global story" in which Europe, the United States and other Western nations cooperate less, endure economic gloom and see their role in the world diminish, Megan Greene, chief economist with Manulife Asset Management, wrote in a research note Monday. WASHINGTON (AP) — U.S.