Which conflict took place from December 31, 1960 to May 7, 1975?

The Vietnam Conflict, also known as the Vietnam War, began with increased U.S. involvement in the late 1950s, specifically around December 31, 1960, when the U.S. started to provide military support to the South Vietnamese government in its fight against the communist forces of North Vietnam. This conflict escalated throughout the 1960s, with significant troop deployments and combat operations occurring until the withdrawal of U.S. forces in 1973. The final end of the conflict is marked by North Vietnam's capture of Saigon on April 30, 1975, leading to the reunification of Vietnam under communist control on May 7, 1975.

Other conflicts mentioned, such as the Korean Conflict, occurred earlier, and the Lebanon Crisis refers to different sets of conflicts and interventions involving Lebanon, primarily during the 1970s and 1980s. Operation Desert Storm, part of the Gulf War, took place in the early 1990s. Therefore, the correct answer is directly tied to the dates labeled, reflecting the significant historical events of the Vietnam War.