A delegation of Vietnamese military and government officials was treated to a tour aboard the sprawling USS George Washington nuclear carrier this weekend. They flew out to the vessel, which was off the coast of southern Vietnam — once home to the US-backed capital of South Vietnam during the brutal Vietnam War.

It’s the second such visit to the US Navy’s hulking carrier in as many years and a symbol of the former foes’ warming military ties. But Saturday’s visit also came amid heated tensions between China and its Asian neighbors.