Why is it said that "immigration to the real border" is conducive to the common stability and development of the frontier and the mainland?

A large number of immigrants have settled in the frontier and established military and agricultural reclamation positions in the frontier, which can be based on it for a long time. This is conducive to improving the economic and traffic conditions in the border areas, enriching the military forces in the border areas, providing an extremely important economic foundation for strengthening the military construction in the border areas, not only alleviating the pain in the rear when the army is fighting, but also supplementing the population and soldiers fighting in the border areas, and can also station heavy troops in the border areas for a long time. In this sense, the strengthening of border defense has actually effectively defended the mainland, so "solid border" is also "solid inside". Third, a large number of immigrants settled in the border areas, which changed the resident structure in the border areas, promoted ethnic integration, improved the local economic model and structure, and thus promoted the progress of the border society.