WASHINGTON (Reuters) - The prospect of Japan and South Korea obtaining nuclear weapons would be incredibly destabilizing, the White House said on Wednesday, a day after leading Republican presidential candidate Donald Trump said the two U.S. allies should build such weapons to deter enemies. “Mr. Trump’s suggestion that somehow we should encourage our allies in South Korea to develop nuclear weapons is directly contrary to a policy that the United States has long pursued and that the international community has long supported,” White House spokesman Josh Earnest told reporters at a daily briefing. 