Trump’s water war with Mexico is just starting

Of the many open fronts Mexico has with Donald Trump, water is the least conspicuous one — but with the biggest potential for immediate damage.The conflict has an historic background: Under a treaty signed in 1944, Mexico needs to send 1.75 million acre-feet of water to the US over five-year cycles, or an average of 350,000 acre-feet per year, from its tributaries into the Rio Grande. At the same time, it expects to receive 1.5 million acre-feet per year from the US through the Colorado River.The pact, hailed as a showpiece of transnational…