If it was a normal situation Zhang Mengyao would give the permission immediately, but it was a different time. Especially after knowing the God Rank could invade Earth at any time in this one month. Lu An was actually the key to every Tang Empire's move against the World Government. She was not sure that the empire was ready to fight without Lu An. While they retreated from Europe, their next goal was to fortify the main territory and expand to the middle east and South East. Lu An returned to report the information he got from Reinar Thamsen. Of course, there were more than the resources that the Giteron Dynasty wanted from the Tang Empire.
i updated the chapter late because i have dentist appointment. Expect for the next chapter to be late as well. My mouth is so uncomfortable right now.