This is the reason Cambodia is so keen to find - something! The reason the disputed territorial waters between Cambodia and Thailand are still unresolved.
The Chinese belt and road programs are building into the country. (Casinos and tourism) The South Koreans too. NGOs with their fleets of Range Rovers, Mercedes Utes and Toyotas are everywhere - and for the masses - scooters. In Phnom Penh at every intersection it is like the merging tributaries of the Amazon with rivers of flowing scooters merging in with the Tuk Tuks and white Lexus RX 350s (the preferred vehicle for the mistresses of important people.)
It's hard to modernise and build good roads without your own oil and gas. (And air conditioning is really useful in the big cities when its real hot and humid...)