Mexican diplomats say climate change has hindered them from settling a massive water debt to the United States, which is bringing economic hardship to South Texas farmers. But a former U.S. federal official on Thursday offered a different explanation. “One of the issues that we see is that domestic problems in Mexico are affecting what’s happening in the United States,” said Maria Elena Giner. “Water is owned by the (Mexican) government, yet they really don’t have good control of the...