After Vietnam's independence, its territory expanded fourfold. What methods did they use?

After a long and arduous struggle with Japan and France, Vietnam officially declared its independence, which is the most familiar one. After Vietnam's independence, the first thing it faced was the occupying power in the south. Compared with mountainous northern Vietnam, the occupying power is flatter and the industry and commerce are more developed. In order to annex and occupy the city, Vietnam and Cambodia in the south jointly occupied the city. However, Cambodia's combat effectiveness is relatively weak, and it can only contain some occupation troops.

After the demise of the Tang Dynasty, the independent State of Yue occupied only a quarter of Vietnam's territory today, namely the Red River Basin with Hanoi as the center. After leaving the territory of China, Yue continued to adopt the strategy of "defending the north and attacking the south" for thousands of years, that is, trying to ease the relationship with China, a far stronger country in the north, and occupying the cities and towns in the south (the predecessor of Cambodia) and Laos in the west. From the Song Dynasty to the Qing Dynasty, it constantly conquered and expanded its territory, and carried out dozens of wars, expanding its territorial area to four times that of independence.

After creating contradictions and occupying cities, Vietnam turned its attention to the Mekong Delta. The land here is fertile and suitable for farming. Vietnam has long had the heart of annexation. Unfortunately, this is the land of Cambodia, an old ally. Vietnam is not good at war. Vietnam began to privately create contradictions between Siam and Cambodia. After the conflict between Siam and Cambodia escalated, Vietnam began to emigrate to the Mekong Delta under the pretext of supporting Cambodia.

Although Cambodia was not satisfied, it had to acquiesce in Vietnam's actions in order to avoid being caught between Scylla and Charybdis. Slowly, the Vietnamese gradually became the main body of the Mekong Delta. By the time Vietnam officially annexed the land, Cambodia was helpless. /kloc-At the end of 0/7, the Mekong Delta fell into the hands of Vietnam, and at this point, the narrow territory of modern Vietnam was formally formed.