because venezuela was officially neutral for most of the war, the task of guarding the venezuelan coast for enemy activity and escorting venezuelan ships was left to the americans. accordingly, after the attack on aruba and curazao where refineries processed venezuelan oil, the united states navy established the fourth fleet, which was responsible for countering enemy naval operations in the caribbean and in the south atlantic. the united states army also sent aircraft and personnel to help protect the oil refineries and bolster the venezuelan air force. to support the mission, venezuela granted american ships and planes access to the country's ports and airstrips.