Woodrow Wilson actually said...
as the conditions on which the Proclamation of March 14, 1912, was based have essentially changed, and as it is desirable to place the United States with reference to the exportation of arms or munitions of war to Mexico in the same position as other Powers, the said Proclamation is hereby revoked
Context
Proclamation 1263—Concerning the Shipment of Arms into Mexico
02/02/1914