What has been, in your opinion, the single biggest military blunder in the books so far (other than Balon’s invasion of the North). Not in terms of consequences necessarily, but just a strategic move totally lacking in sense or reason in its singular stupidity?

In AGOT: tossup between Edmure’s defense of the Riverlands and Jaime’s attack at Whispering Woods. 

In ACOK: Balon’s invasion of the North. Battle of the Fords counts for consequences, but makes a basic sense. 

In ASOS: does Duskendale and the Ruby Ford count, given that they’re intentional losses? 

In AFFC: Euron sending the Iron Fleet to Essos right after invading the Reach. Cersei’s blunders are mostly political, but shipping out the new royal fleet?

In ADWD: Dany’s inaction in Meereen, basically letting herself get besieged without a fight.