Brinkmanship is the answer M8
No person except a natural born citizen, or a citizen of the United States, at the time of the adoption of this Constitution, shall be eligible to the office of President; neither shall any person be eligible to that office who shall not have attained to the age of thirty-five years, and been fourteen years a resident.
World War I began in 1914, after the assassination of Archduke Franz Ferdinand, and lasted until 1918.
Hope This Helps! Have A Great Night!