The question, of course, is how.
His Majesty is willing to dedicate significant resources to your general concept of a national tour that will make the case for war to all corners of the land. But in order to spend royal dollars, you need some overall idea of the nature of the tour you intend to spearhead:
It shouldn't be greatly difficult, given that you've observed that the nature of the charges against the Fein Empire is widely known in the city of Hondelet, at least. Considerable outrage bubbles up naturally from Brentons that a foreign power should feel free , with impunity, strike directly against the person of the King.
With Kitty Harlowe's help, you recruit a full troupe of performers, from acrobats and musicians to fellow fools. A little-used barn is cleaned for your purposes. The first day you look across the assembled throng and prepare to address them takes you back to those early days in the employ of Duke Ruffino. A motley crew we were then, you think with a smile. This assemblage shall do much greater things.
"Here is our task, compatriots," you say, projecting throughout the lofty barn, gathering attention to yourself. "Our countrymen are outraged at what the Fein have done; our task is to take that outrage and temper it, as steel, into a weapon of war."
The performers look at each other. "Outrage…as a weapon?" a drummer asks, tilting her head.
"Oh, just wait," you say with a smirk.
Onward