"US Secretary of Defense Mark Esper has urged all South China Sea claimant countries, including the Philippines, to take a “very public posture” and assert their sovereign rights against China’s aggressive moves in the disputed waters. Esper also said the United States was open to revisiting and strengthening its Mutual Defense Treaty (MDT) with the Philippines “based on changes in the environment and world situation.” Ambiguities At a press conference with Esper on Tuesday, Defense Secretary Delfin Lorenzana said he initially introduced the idea of revisiting the MDT which was signed by the two countries in 1951. Lorenzana cited the ambiguities in the treaty, including a provision that indicates that an attack on “Metropolitan Philippines” would automatically trigger a military response from the United States. Esper meanwhile reiterated the US commitment to the MDT which covers the entire Pacific region, including the South China Sea..."