This picture depicts the Pathet Lao, the Lao communists defeating the Americans who supported the Royalist government. Notice the bomb with 'USA' written on it. This is in Viengxay, Huaphan Province where the Pathet Lao hid in caves for 10 years from the 1960s while it was being bombed. It is near the Vietnam border in the North East of Laos.
The USA was concerned that if Laos became communist, communism would take over the world. That's why they bombed the communists.
I visited the 400 caves where 10,000 hid for 10 years. There were a few years of bombing. They hid until the cease fire agreement was signed. The caves were quite interesting. There were enlarged natural caves, and caves they made. There are seven open to tourists. There was a cave that was a theatre. They built some emergency rooms in case there was chemical warefare that had a Russian air filter to pump in clean air. I doubted that it would have worked. We saw the bedroom of the former President and Prime Minister Kaysone Phomvihane.