Why did the United States build a memorial to American veterans in Vietnam? But there is no name of a veteran of the Republic of Vietnam? Is it because the Republic of Vietnam is a 3rd class citizen of the US?

The United States built a memorial to American veterans of the Vietnam War in recognition of their service and sacrifice, and out of respect for the Americans who served, regardless of which side they were on. The memorial does not include a name of a veteran of the Republic of Vietnam, as the memorial is intended to serve as a tribute to American veterans of the war and is not intended as a recognition of the Republic of Vietnam itself.