The Brexit vote is having a worldwide economic effect, and Asian countries, though detached from the political negotiations in Europe, are bracing themselves against the uncertainty. The South Korean finance ministry announced Tuesday a 20 trillion-won ($17.1 billion) stimulus package and a cut to its internal growth forecast. In Japan, the government has already held one emergency meeting this week with the Bank of Japan to discuss market conditions and will hold another the morning of June 29. China, for now, seems more worried about the long-term implications of Brexit and particularly about the impact it might have on global trade....