Burnham is a mutineer. She nerve pinched her Captain and tried to start a war. Oh she did.
Correction, she tried to PREVENT a war because the Klingons only deal with fellow warriors with respect. It's just she missed the fact it was impossible to avert. T'Kuvma wasn't testing the waters, he was there to invade.
BE THAT AS IT MAY:
She ruined their chance of ending the war before it began by executing T'Kuvma, though.
She basically made the wrong choice from Call of Duty: Black Ops 2 and made Cordis Dei a real religion.