2/2
You misunderstand Romans (no surprise that): Paul taught (much as Jesus did: Render unto Caesar ...) that Christians should accept secular (pagan) authority over them -- not that they should seek it, accept it, or exercise it themselves.  God could and did use the pagans for his purposes.  Christians were under their authority, and in light of the expectation of the imminent return of the Lord, they were not to resist that authority; God was using it.