Pusillanimous

The soldier deserted his troop in a pusillanimous manner.

Source: wiktionary

Therefore, the wise thing is for us diligently to train ourselves to lie thoughtfully, judiciously; to lie with a good object, and not an evil one; to lie for others' advantage, and not our own; to lie healingly, charitably, humanely, not cruelly, hurtfully, maliciously; to lie gracefully and graciously, not awkwardly and clumsily; to lie firmly, frankly, squarely, with head erect, not haltingly, tortuously, with pusillanimous mien, as being ashamed of our high calling.

Source: wiktionary

(Aaron Burr and Andrew Jackson ride together in Tennessee; Burr narrates): Jackson shouted at me his view of the duel. "Never read such a damned lot of nonsense as the press has been writing! All that hypocritical caterwauling for that Creole bastard (referring to Alexander Hamilton) who fought you of his own free will, just like a gentleman which he wasn't, if you'll forgive me, Colonel! I know you couldn't have met him unless you thought he was one, but he was not, Sir. He was the worst man in this union, as you, Sir, are the best. The best, and that goes for that pusillanimous spotted caitiff of a president (referring to Thomas Jefferson) we got.

Source: wiktionary

Octavian, by contrast, was pusillanimous in battle ... but proved himself extremely adept in the political arena

Source: wiktionary