Secretary of Defense Mark Esper has authorized the use of $3.6 billion in military construction funds for 11 wall projects on the southern border with Mexico, according to defense officials and a letter from Esper to the Senate Armed Services Committee, which has been obtained by CNN. In his letter, Esper told Congress he has "determined that 11 military construction projects along the international border with Mexico, with an estimated total cost of $3.6 billion, are necessary to support the use of the armed forces in connection with the national emergency." The announcement fulfills a promise made by President Donald...