April 15, 1917, 11:03: Mexico easily occupied many borderlands in Texas and Arizona, but the Americans entrenched in California were putting up a formidable defense, and Mexico was not expecting Trenches to pop up this soon. Mexico's plan was to push in as far as possible until the Americans were able to recover from the initial shock of the invasion, then they would entrench until German reinforcements could arrive. The Americans prepared much sooner than expected, and the Mexicans had to entrench in California. at 11:03 on April 15, Wilson's meeting with Russian, French, and British diplomats in Ottawa ended with the U.S. officially joining the Entente(Russia was still reeling from the February Revolution, but they were able to spare a few politicians). British forces quickly halted the desperate Mexican attack on Belize, and it devolved into trench warfare very quickly. In less than a week, the new American front devolved into the same stalemate that was plaguing Europe.