It had a clandestine mission of economically pacifying those same worlds. BEAT made the Periphery economies as dependent on spaceborne commerce as possible.
After the war, the Star League did not end its attempt to subjugate the Periphery economically; they just took a more pragmatic approach. Rather than making all of a planet's industry directly dependent on interstellar trade, they focused on two areas, power production and water purification. Fusion plants and water purification facilities are very capital intensive installations, requiring a vast amount of high-tech machinery to construct and a constant flow of spare parts to operate. The investment needed to construct a facility to produce the unnecessary parts to build such an installation is enormous, but once built, such a facility can support the construction and subsequent maintenance of 500 power or water purification plants. Make the facility marginally larger and it could support over a thousand plants. It was the flow of these critical supplies that the Star League controlled.
The actual production facilities were located in the Inner Sphere, and built with Star League funds. Because of the large production runs and general economic efficiencies of the giant plants, spare parts could be sold profitably to Periphery facilities at prices that no Periphery manufacturer could match. Within 10 years, 94.8 percent of the Periphery's fusion power plants, and 81 percent of its water purification plants depended on spare parts from the Inner Sphere. Of the Periphery's 237 small manufacturing firms supplying spare parts to these two industries, only 6 reminded in business by 2620.
From Accessory the Periphery.Some of the first targets were these same massive production facilities whose products kept the Periphery under control. The remainding production was used to keep the Inner Sphere planets from totally falling into barbarism.
Divide and Conquer, "An Historical Economic Analysis of the Periphery and its Consequences for the Current Balance of Power, by Professor Lewis Samuel, Comstar Press, Terra, 3023.
There's a quote in the RPG material somewhere about there being only 20(?) fusion powerplant generators supplying all fusion reactors during the Succession war......... I try to verify this.