The U.S. augmentation forces to be deployed to the Korean peninsula in the event of a war to support the defense of the ROK, consist of 690,000 ground, naval and air force troops, 160 vessels and 2,000 aircrafts. Pursuant to Article 2 of the Mutual Defense Treaty between the ROK and the U.S., the augmentation forces are to be increased progressively based on how the crisis situation develops, in two different modes; namely, the Flexible Deterrence Options (FDO)9) and the Time Phased Force Deployment Data (TPFDD).10) The FDO are enacted during the initial stages of a conflict when the level of crisis rises in the Korean peninsula, to deter war and mitigate the crisis situation by deploying designated forces. If the attempt to deter war fails, combat and support forces, as pre-planned under the TPFDD, will be deployed Chapter 3 to execute the ROK-U.S. combined operation plans. 9) a series of political, economic, diplomatic and military options that are part of the crisis action procedures laid out in the CFC Crisis action Standard Operating Procedures, which have to be promptly executed to deter war. 10) Force deployment list and data of the U.S. augmentation Forces for the execution of combined operational plans. Section 1 Military Organization and Forces 53