Unable to choose the correct meaning of betray

In this question, if I take betray to mean ‘reveal unintentionally’, follow fits the second blank. But if I take betray to mean ‘desert in times of need’, brandish fits the second blank. Is there something I’m missing? How can I choose the correct option in this scenario?

Also, is there anything wrong with the way I used the math strategy? The sentence before the second blank says that ‘he doesn’t follow a fixed set of principles’. After that there is ‘however’. So, won’t the opposite of that be ‘piously follow political principles’?

Thanks in advance.

what makes this question difficult is that ‘pious’ is not a synonym of devout here but rather a synonym of insincere/hypocritical. so the answer is brandish.

your three pairings are:
idealistic—strategic (+, -)
brandish–betray (+, -)
unchanging higher purpose–deeply felt moral code (+, +)

What do you do when you’re torn between different meanings of a word in a sentence?