Mule had no fresh information about the nature and powers of Second Foundation before they attacked. And finding and attacking Second Foundation became insufficient after Second Foundation attacked. If Second Foundation operatives could infiltrate Mule´s empire to take down his Converted people, then destroying Second Foundation headquarters could not have stopped Second Foundation operatives under cover inside Mule´s Empire from continuing their mission. And that if there WERE Second Foundation headquarters for Mule to find and destroy: these headquarters might have been abandoned as Second Foundation members went to Mule´s empire to attack, or never have existed in the first place.
The logical thing for Mule to try was use the fact that Second Foundation had finally revealed a modus operandi. Try to catch Second Foundation operatives in the act, and milk them for information about Second Foundation, their coconspirators, and how best to thwart and catch the others.
How to fight Second Foundation?
And finding and attacking Second Foundation became insufficient after Second Foundation attacked. If Second Foundation operatives could infiltrate Mule´s empire to take down his Converted people, then destroying Second Foundation headquarters could not have stopped Second Foundation operatives under cover inside Mule´s Empire from continuing their mission. And that if there WERE Second Foundation headquarters for Mule to find and destroy: these headquarters might have been abandoned as Second Foundation members went to Mule´s empire to attack, or never have existed in the first place.
The logical thing for Mule to try was use the fact that Second Foundation had finally revealed a modus operandi. Try to catch Second Foundation operatives in the act, and milk them for information about Second Foundation, their coconspirators, and how best to thwart and catch the others.