they already do. China wields strong economic influence and pressure over her southeast asian partners, some of whom need to be convinced to give up significant portions of maritime control and territorial rights in an effort to redraw the american sphere of influence in the south china sea region, and further out to establish a new economic status quo in africa and S. Am, where the traditional western world's influence is more political than economic.
In 1984 Big Brother did this same thing by having perpetual war, and Chinese military spending is in fact stupendously huge, but even so they aren't actually in a war so need other ways to burn large quantities of capital. Building unprofitable railways in the middle of Africa is a great way to keep their own people poor whilst claiming some sort of moral high ground. But if these were good investments, it wouldn't be up to the PRC to make them.
A) Reach a predetermined level of technology you are comfortable with |OR| B) Look spacewards.
Very hard to do both of those.