Which operation did the Marines participate in during the conflict in Grenada?

The operation in which the Marines participated during the conflict in Grenada is known as Operation Urgent Fury. This operation took place in October 1983, following a coup that led to instability on the island, creating a threat to American citizens and interests. The mission aimed to restore order, protect American lives, and ensure the safety of the students participating in a medical school in Grenada.

During Operation Urgent Fury, Marine units were integral to the initial assaults and played significant roles in securing key locations. The operation was marked by rapid deployment and showcased the U.S. military's ability to respond swiftly to crises.

The other options refer to different military operations that occurred in various contexts: Operation Desert Storm was primarily related to the Gulf War in 1991; Operation Just Cause focused on the invasion of Panama in 1989; and Operation Joint Guard was part of NATO's peacekeeping efforts in the Balkans during the mid-1990s. Each of these operations is significant in its own right but pertains to different conflicts and timeframes than Grenada.