A speech by British Prime Minister Theresa May on Tuesday answered the biggest outstanding question about the United Kingdom's impending departure from the European Union: It will not try to stay in the bloc's single market. Instead, May explained, her government will push for a comprehensive free trade agreement with the European Union. She emphasized that regaining control of immigration policy would take precedence over remaining a member of the EU single market. But while her speech clarified some questions about the Brexit process and the United Kingdom's future course, it left several major issues unaddressed....