During the years 1917-1918 Mexico stood at the crossroads between revolutionary nationalism and foreign control. Nevertheless, much of the diplomacy of this wartime period and the variety of foreign threats to the regime of Venustiano Carranza remain obscure. Only very recently have scholars (Glaser, 1971; Machado and Judge, 1971; Trow, 1971; Tulchin, 1971; Smith, 1972; Meyer, 1968) realized the extent of the American movement for armed intervention in Mexico in 1919. But the more subtle strategy to guide the Mexican government's policy through economic pressure has received little attention. Likewise, the anti-Carrancista policy of the British Foreign Office has been ignored (see Fabela, 1958-1959; López de Roux, 1965; Zorrilla, 1965; Smith, 1969, 1972; Meyer, 1968). If one focuses less on the possibilities of overt military intervention and more on the economic issues of monetary exchange, food, loans, and oil, the years 1917-1918 (usually quickly sandwiched between the Pershing incursion and the 1919 interventionist movement) acquire major significance.