Final answer:
The Mexican minister to the US likely left due to strained relations following the US occupation of Veracruz, the attack on Columbus by Villa's forces, and Carranza's refusal to accept US military intervention as Mexico grappled with internal revolution.
Step-by-step explanation:
The Mexican minister to the US likely left his office in Washington due to the escalating tensions and diplomatic breakdowns between the United States and Mexico during the early 20th century. These tensions were exacerbated by events such as the occupation of Veracruz by U.S. forces in April 1914, and the subsequent battles that led to both American and Mexican casualties. Furthermore, the attack on Columbus, New Mexico, by Pancho Villa's forces in March 1916, and the U.S.'s retaliatory Punitive Expedition into Mexican territory to capture Villa, contributed to strained relations. Mexican President Venustiano Carranza's increasingly assertive stance on maintaining Mexican sovereignty and pushing back against U.S. interventions led to a decline in diplomatic relations, potentially prompting the Mexican minister's departure.
Amid the chaos of the Mexican Revolution, with leaders such as Francisco Madero, Victoriano Huerta, Emiliano Zapata, and Pancho Villa challenging the status quo, Mexico experienced internal conflict that made it difficult to focus on international diplomacy. President Woodrow Wilson's support of Carranza, followed by the dispatch of American troops into Mexico, damaged the relationship further. By 1917, Carranza had consolidated power, but the continuous rebellion and the U.S.'s military presence on Mexican soil, viewed as an insult to national sovereignty, made diplomatic engagement challenging.