Secure United States Bases Act This bill revises requirements related to U.S.-based foreign military training programs. Specifically, the bill creates a visa category for certain aliens who have been accepted into a U.S.-based military training program; adds application, vetting, and monitoring requirements for foreign military trainees; and requires the Department of Defense to develop a method for classifying the relative risk, by country, of accepting foreign personnel into U.S. military training programs.