Nope it belongs to us. Your close neighbours knows what Vietnam is like. Nothing but a small aggressor, explains why Laos, Cambodia, Myanmar and Thailand are siding with us, not your country. All Vietnam was good for was the Cambodian invasion, Attacking Thailand, Laos, trying to steal China's territory, threatening to enter Malacca Straight and illegally importing Timber from Laos. No wonder your neighbours love you so much
Vietnam liberated Cambodian people from Kh'mer Rouers backed by China 1975 -1979, be course they attacked us first with chinese advisers stationed in Phnom Penh. Then we handed power over to Cambodian.
Thailand permitted USA air force using air port in Thailand to attacked Vietnam in Vietnam war, we had done some actions to warning him not playing with fire.
Vietnam helped Laotian people to get Independence up to now. China to day have a diplomacy relation with Lao's Government.
You have to learn more truth of fact before spamming like Chinese propaganda.